Review Article Pressure Sensor: State of the Art, Design ...downloads.hindawi.com/journals/js/2015/846487.pdf · Journal of Sensors load cells, pressure indicating lm, and tactile

Review ArticlePressure Sensor State of the Art Design and Application forRobotic Hand

Ahmed M Almassri1 W Z Wan Hasan1 S A Ahmad1 A J Ishak1 A M Ghazali1

D N Talib1 and Chikamune Wada2

1Department of Electrical and Electronic Engineering Faculty of Engineering Universiti Putra Malaysia (UPM) 43400 SerdangSelangor Malaysia2Graduate School of Life Science and Systems Engineering Kyushu Institute of Technology 2-4 Hibikino Wakamatsu-kuKitakyushu 808-0196 Japan

Correspondence should be addressed to Ahmed M Almassri engahmed8989gmailcom andW Z Wan Hasan wanzuhaupmedumy

Received 5 November 2014 Accepted 15 December 2014

Academic Editor Guangming Song

Copyright copy 2015 Ahmed M Almassri et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

We survey the state of the art in a variety of force sensors for designing and application of robotic handMost of the force sensors areexamined based on tactile sensing For a decade many papers have widely discussed various sensor technologies and transducermethodswhich are based onmicroelectromechanical system (MEMS) and siliconused for improving the accuracy andperformancemeasurement of tactile sensing capabilities especially for robotic hand applicationsWe found that transducers andmaterials such aspiezoresistive and polymer respectively are used in order to improve the sensing sensitivity for graspingmechanisms in futureThispredicted growth in such applications will explode into high risk tasks which requires very precise purposes It shows considerablepotential and significant levels of research attention

1 Introduction

Robotic hand is a mechatronic machine that is made tocomplete assignment whenever it is required especially forrepetitive and dangerous tasks and also during specificapplications such as military robots home automation [1]automotive industries and nuclear industry robots In factmany robotic hand applications were already developed asin [2 3] for instance dexterous manipulation [4ndash6] tactileimage perception [7 8] artificial limbs [9] fingerprintrecognition [10] grasping objects [11ndash13] and pick and placeapplications [14 15] can also be widely seen in variousindustries Nonetheless some of these robotic applicationsrequire a lot of labor force notably in terms of assembly lineand material handling

Henceforth there is a significant need to have a dedicatedmachine which is suitable for robust robotic applicationFor example robotic hands manufacturing industries forpick and place mechanism are programed to complete task

where it takes a product from one spot and put it to adifferent location This technology has the advantages ofreducing the risk process associated with human operatorsduring the manufacturing process Besides it also saves timeand energy required for the labor Therefore tactile sensingin the robotic hand is defined as a sensor device that isgood enough to measure various properties of an objectand provide information through physical touch betweena sensor and an object [16] Recently the enhancement ofthe robotic hand sensor has received a substantial attentionand becomes crucial to our everyday life Researchers haverecognized that equipping a robot with different sensors isa way to perform tasks in unstructured environment andenable the robot to cope with significant uncertainties Dueto the demand of ensuring safety between robots and objectsduring the mechanical touch intelligent tactile sensing inrobotic hand with high capabilities is critical

In this paper the different techniques formeasuring forceor interface pressures are presentedThese techniques include

Hindawi Publishing CorporationJournal of SensorsVolume 2015 Article ID 846487 12 pageshttpdxdoiorg1011552015846487

2 Journal of Sensors

load cells pressure indicating film and tactile pressuresystem Similarly a review on industry pressure sensingthat involves the pick and place applications and algorithmcontrol is also highlighted The paper also discusses theMEMS sensor technology and different types of sensorswhile the last section of this part discusses the piezoresistiveflexiForce sensor FlexiForce sensor has a good substratematerial which is a polymer that enhances the force sensingand improves the performance of force linearity hysteresisdrift and temperature sensitivity compared to any other thinfilm Furthermore it is flexible and ultrathin enough as theresearchers and designers can use it in different integratedapplications as well as for applications that are orientedto manipulative tasks with grippers of robotic hand In anutshell new applications for tactile pressure sensing show ahigh increase in publications and research attention as viewedin Table 2 As a result the design of sensor becomes moreprecise with higher reliability to overcome the problems

2 Sense of Pressure Methods

Pressure is force per unit area applied in a direction perpen-dicular to the surface of an object The formula is commonlywritten as follows

119875 =119865

119860 (1)

where 119875 is the pressure 119865 is the normal force and 119860 isthe area of the surface of contact When two objects arecontacted they exert force on each other Thus the averageinterface pressure is the total force divided by the interfaceregion In contrast pressure measurement is necessary to geta peak pressure when the interface pressure is not uniformlydistributed In this context there are three technologies andmethods to be considered to measure force or interfacepressures load cells pressure indicating film and tactilepressure sensor

21 Load Cell Load cell is a type of pressure sensor which iscommonly used in industrial weighing product to measureforce such as goods and vehicles The gripper of a robotichand that picks up an object can be equipped with loadcells in order to provide compression force feedback tothe control system which prevents damage to the object orreleased too early Also load cells can be used to measure thecompression forces during a robot walk to provide data forthe equilibrium-controlling system In industrial machineryrods beams wheels and bars are instrumented in orderto control the forces exerted on them Due to this varietyof possible applications load cells are very important [23]There are many types of technologies which are used tomeasure loads such as strain gauges piezoelectric elementsand variable capacitance

Moreover depending on the applied force andmechanicsof application multiple form factors of load cells are utilizedTypically multiaxis MEMS force-torque sensors are usedto measure the load In the literature a small numberof multiaxis MEMS sensors have been reported In [24]

LCLC

LC LC

Figure 1 Pressure measurement using multiple load cells [30]

a capacitiveMEMS force sensor is presented which assess theforce along two axes In [25 26] the design of a piezoresistivethree-axis force sensor is described A piezoresistive torquesensor has been presented in [27] In addition a three-axiscapacitive MEMS force-torque sensor has been reported in[28] and this sensor is able to measure forces along two axesand a torque perpendicular to these forces Aswe know forcescan be sensed in a plane while a torque perpendicular to thisplane can bemeasured In certain conditions researchers canusemultiple load cells tomeasure forces overmultiple regionsof a contact interface [29] In Figure 1 an interface or contactarea is divided into four quadrants with an exclusive loadcell measuring each area This arrangement provides moredetails on the force distribution across the surface the averagepressure in each zone will occur Still the disadvantage of thistechnique is inconsistent because the load cell can show thetotal force but cannot identify localized spikes in pressureThere are many different types of load cells that operate indifferent ways but currently the most commonly used loadcell is the strain gage (or strain gauge) load cell

211 Strain Gauge Load Cells Strain gages are small patchesof silicone or metal that measure mechanical strain andconvert the load acting to electrical signals This load cell isconsidered as an analog type tool and utilized to measureweight When a load is applied to a stationary object stressand strain are the result Stress is defined as the objectrsquosinternal resisting forces and strain is the displacement anddisfigurement that occurs [31] so the load causes deforma-tions in the material or object that can be measured usingstrain gauges Two capacitive pressure gauges which havebeen used extensively in the study of liquid and solid heliumare described [32] Figure 2 illustrates a structure of straingauges Here more resistance in strain gauge will increasethe stability as seen in Figure 2 In fact it also offers a widerange of different patterns which means various applicationswill occur

22 Pressure Indicating Film Pressure indicating film iswidely used to measure interface pressures between two

Journal of Sensors 3

Gauge length

Strainresistor

Tab

Backing

Figure 2 Structure of strain gauge [31]

Polyester baseMicroencapsulatedcolor-forming layerColor-developing layerPolyester base

A-film

C-film

Figure 3 Components of pressure indicating film [30]

surfaces Two sheets of polyester are designed to measurethe force applied across the sensing area Figure 3 showsa pressure indicating film Here a colour material undera layer of polyester is layered next to tiny microcapsuleswhich are utilized to break under different pressures Whenpressure is applied to the film the microcapsules are brokenand distributed ink where pressure is deformed and thecolour intensity of the resulting image reveals the relativeamount of applied pressure As a result the greater thepressure the darker the colour and an image of the forceapplied will be composed across the sensing area Variousfeatures cause the pressure indicating film to be used in awide range of applications including flexibility being easyto use and thinness that plays a major role in capturingimage of applied pressure Furthermore there are no attachedelectronics that is a good material or film to obtain thepressure distribution without concern of crushing wires orexpensive electronics during the film feeding through rollersPressure indicating film is used in applications that requiresstatic pressuremeasurements visual pattern of peak pressureand one-time use [30]

23 Tactile Pressure Sensor Tactile pressure sensor measuresvarious parameters of an object through physical touchbetween sensor and an object [16] The measured parametersare namely pressure temperature normal and shear forcesvibrations slip and torques In this context pressure andtorque are example of an important parameter and it istypically measured through physical touch Detection andmeasurement of a point contact force can also be consideredas a part of touch sensor for pressure and torque butthen again tactile sensing can also ease up the process

Conductive silver

Adhesive anddielectric layers

Flexible substrates

Semiconductive material

Figure 4 Construction of a tactile pressure sensor [30]

of interpretation of the corresponding information for theparameter

By definition tactile sensing means an array of a coordi-nated group of touch sensors [33] A common type of tactilepressure sensor consists of an array sensor For instanceFigure 4 shows a unique piezoresistive material sandwichedbetween two pieces of flexible polyester each half of themhas printed silver conductorsThe result is a very thin 000410158401015840(01mm) sensor which can be used in various applicationsespecially for industrial and medical robot A conductivetrack which is composed of silver conductors will scan theelectronics and transmit a signal through the piezoresistiveink The tactile array sensor signal can be processed to offera great deal of parameters about contact kinematics andprecise tactile information for robotics haptic feedback andother contact applications Among the parameters that canbe extracted are contact location object shape and effectivewidth of the pressure distribution

The pressure distribution can be achieved by identifyingthe position of all the applied forces To do this an arraysensor which has vertical and horizontal of piezoresistivetraces is needed Here each row and column intersecting inone point are called a sensel More intersection implies moresensels whichmeans themore spatial resolution is the sensorBecause of many human machine interfaces (eg wheelchairseating systems driverrsquos seats bed mattresses hospital beds)[34 35] and because human joint is incongruent the sensorshould be in a wide range of resolutions However the tactilepressure sensor array has a good spatial resolution of thepressure distribution Figure 5 illustrates the sensing systemand an electrical schematic of electronics that scan eachsensel When force is applied to the sensel the sensel whichis represented by a variable resistor will be changed andthe possible current will flow through the device and thenthe electronics will collect the analog data which can becompensated with proper calibration

From the reviews that have been obtained there areseveral factors to be considered specifically on technologyfor interface force and pressure measurement between two


Test voltageScanning electronics

DigitaloutputAD

Control circuit

Sensor array

Figure 5 Electric schematic of sensor [30]

surfaces for robotic hand applications purposes Compar-isonwise load cells provide the most reliable data pressuremeasurement but the size and number of load cells limit thedensity of measurement points The total load can be easilyreported however the size of the load cell can be a limitingfactor when it reaches fine granularity due to its pressuredistribution

Pressure indicating film can be used in variety of appli-cations such as robotic hand but the nature of the film willonly provide the peak pressure between interfaces during ameasurement This has obvious limitations when trying tomeasure dynamic applications and also the resulting datapressure measurement has less accuracy whereas tactilepressure sensor can provide detailed dynamic measurementsof interface pressure with minimal impact on system dynam-ics The sensing elements need to be properly calibratedto provide accurate data but the resulting measurementswill provide the most in-depth analysis of interface systemdynamics Depending on the information needed and thephysical constraints of the system being measured load cellspressure indicating film and tactile pressure sensors eachhave advantages and constraints for providing accurate andmeaningful data pressure measurement Understanding howthese strengths and limitations influence an application iscrucial

3 Pressure Sensor Design and Technology

A sensor is a device that measures a physical quantity andconverts it into a signal which can be read by an observeror an instrument There are various types of sensors thermalsensor electromagnetic sensor mechanical sensor pressuresensor and others Pressure is sensed bymechanical elementssuch as plates shells and tubes that are designed andconstructed to deflect when pressure is applied Deflectionof the elements must be transduced to obtain an electricalor other output Pressure sensor can differ in technologydesign performance application suitability and cost It canbe classified based on various transduction principles suchas resistivepiezoresistive tunnel effect capacitive opticalultrasonic magnetic and piezoelectric The relative merits

Ω

F

Figure 6 Piezoresistive tactile pressure sensor [38]

and demerits of different transduction methods are givenin Table 1 Worldwide there are hundreds of different tech-nologies used in pressure sensor designs such as sensing ele-ment method material MEMS nanotechnology and othersFurthermore there are significant differences in the types ofpressure sensor results from different material used as well astheir functional properties

Recently pressure sensor using MEMS technology hasreceived enormous attention due to various advantages overtraditional electromechanical sensing technology MEMSoffers small size lowweight low cost high performance largescale integration low power consumption wider operatingtemperature and higher output signal [36] This sectiondiscusses in detail the three main types of pressure sensormethods for robotic hand application piezoresistive piezo-electric and capacitive pressure sensor Also various designsand technologies of the pressure sensor are explained in thissection

31 Piezoresistive FlexiForce Sensor As sensor technologygrows these days there are many types of sensors that havebeen used for pick and place application especially resistivemethod due to its stability and high sensitivity Piezoresistivesensors use the change of the electrical resistance in amaterialwhen it has been mechanically deformed The resistance of apiezoresistor is given as follows

119877 =120588 times 119897

119905 times 120596 (2)

where 120588 119897 119905 and 120596 denote the resistivity length thicknessof the piezoresistor and the width of the contact respec-tively Figure 6 shows an example of the piezoresistive tactilepressure sensor Due to the various features of piezoresis-tive including low cost good sensitivity relatively simpleconstruction long-term stability with low noise accuracyand reliability it shows the maturity of the technology Inaddition the sensor is considered easy to fabricate and inte-grate with electronic circuit according to the characteristicof the piezoresistive material However it can measure onlyone contact location and it will still need external powerThough this limitation has been improved by [37] that allowsmeasuring many contact points by using parallel analogresistive sensing strips

The force sensing resistor (FSR) is based on piezoresistivesensing technology It can be made in a variety of shapes and


Table 1 Relative merits and demerits of various tactile sensor types [17]

Type Merits Demerits

Resistive (i) Sensitive(ii) Low cost

(i) High power consumption(ii) Generally detect single contact point(iii) Lack of contact force measurement

Piezoresistive

(i) Low cost(ii) Good sensitivity(iii) Low noise(iv) Simple electronics

(i) Stiff and frail(ii) Nonlinear response(iii) Hysteresis(iv) Temperature sensitive

Tunnel effect (i) Sensitive(ii) Physically flexible (i) Nonlinear response

Capacitive(i) Sensitive(ii) Low cost(iii) Availability of commercial AD chips

(i) Hysteresis(ii) Complex electronics

Optical

(i) Physically flexible(ii) Sensitive(iii) Fast(iv) No interconnections

(i) Loss of light by micro bending chirping(ii) Power consumption(iii) Complex computations

Ultrasonic (i) Fast dynamic response(ii) Good force resolution

(i) Limited utility at low frequency(ii) Complex electronics(iii) Temperature sensitive

Magnetic

(i) High sensitivity(ii) Good dynamic range(iii) No mechanical hysteresis(iv) Physical robustness

(i) Suffer from magnetic interference(ii) Complex computations(iii) Somewhat bulky(iv) Power consumption

Piezoelectric (i) Dynamic response(ii) High bandwidth

(i) Temperature sensitive(ii) Not so robust electrical connection

Conductive rubber (i) Physically flexible (i) Mechanical hysteresis(ii) Nonlinear response

sizes and can be utilized in many applications in order tomeasure a proportional change in force and rate of changeand also detects contact or touch between objects FlexiForcemanufactured Tekscan is one of the most piezoresistivesensors widely used in robotic hand Figure 7 shows a tactileforce sensor or FlexiForce sensors This sensor is consideredone of the best ideal force sensors for designers researchersor anyone who needs to measure forces With its thinconstruction flexibility and force measurement ability theFlexiForce sensor can measure the force between any twosurfaces and is resilient to most environments FlexiForce hasbetter force sensing properties linearity low hysteresis driftand temperature sensitivity than any other thin film forcesensors according to the good substrate material which is apolymer This material has been considered suitable enoughto use in robotic hand for grasping objects effectively

The structure of the force sensor is a substitute of amatrixof sensing traces the ink uniformly covers an area tomeasurethe total force applied to that space The sensor consists oftwo layers of substrate as shown in Figure 7 This substrateis formed of polyester film and a conductive material silverwhich applies to each layer Layer of pressure sensitive ink isthen used followed by adhesive to combine the two layersof substrate together to compose the sensor Additionallythe FlexiForce sensor decreases the resistance of the sensingelement when the force applied increases In this contextvarious applications using FlexiForce sensor are implemented

by many researchers [39] As an example measurementof interface pressure or force between two soft objects ispresented in [40] Teleoperated robotic systems using tactileforce sensor for the design and development of a low costcontrol rig to intuitively manipulate an anthropomorphicrobotic arm with gripping force sensing are reported in [41]The measurement of low interface pressure between the skinsupport surfaces and pressure garments is also discussedin [42] Thereupon one good example of using FlexiForcesensors is pick and place application which offers to achievehigh sensitivity and minimize slip movement and weightmeasurement with a secure grasp

32 Piezoelectric Pressure Sensor Piezoelectric sensors con-vert an applied stress or force into an electric voltage [43]Piezoelectric material is considered a smart material due toits property which can be used as a sensor and actuatorsFurthermore the piezoelectric materials also have highsensitivity with high voltage output when force is appliedThe sensitivity of piezoelectric force sensors is measuredin terms of CN with sensitivity reported up to 130pCN[39] Piezoelectric is considered as a passive sensor whichoffers a high reliability that is useful to be applied in variousapplications Yet it is only suitable for detection of dynamicforces because of the voltage output decreases over time[44] because it is not able to measure a static force due totheir large internal resistance [45] Piezoelectricmaterials like


Table2Pressure

sensor

with

vario

usapplications

basedon

different

transductio

nmetho

ds

Year

AuthorRef

Transducer

metho

d

Array

numbero

felem

ents

Material

type

Forcepressure

sensitivityor

resolutio

n[N]

Forcepressure

sensitivityor

resolutio

nrange[

N]

Application

Limitatio

ns

Advantages

Weakn

ess

2013

Asadn

iaetal[18]

Piezoelectric2times5

Liqu

idcrystal

polymer

3mmsminus1(N

o)mdash

Und

erwater

sensing

(auton

omou

s)

(i)Detectverylow

frequ

ency

(dow

nto

01H

z)in

water

(ii)H

ighresolutio

n(3mmsminus

1 )(iii)Self-po

wered

and

passively

sense

underw

ater

objects

(i)Ap

pliedun

derw

ater

2012

Aqilahetal[19]

Resistiv

e4times4

Con

ductive

rubb

er15kgcm

2(N

o)mdash

Robo

tichand

(i)Flexibilityand

stretchability

(ii)L

inearity

(i)Needexternalpo

wer

(ii)M

axim

umpressure

islow

2010

Choi[4]

Strain

gauge4times4

Polymer

2066m

V(N

o)701mV(Sh)

0ndash08(N

o)(Sh

)Dexterous

manipulation(rob

otic

fingertip)

(i)Measure

norm

aland

shearloads

simultaneou

sly

(i)Lo

wforcec

apacity

(06N)

2009

Nod

aetal[20]

Piezoresistive

mdashSilicon

rubb

er001(N

o)01

(Sh)

005ndash3

(No)

005ndash3

(Sh)

Dexterous

manipulation(rob

otic

application)

(i)Highsensitive

sensor

(i)Com

plex

desig

n(ii)Infl

exibility

2008

Leee

tal[9]

Capacitiv

e8times8

Polymer

25

mN(119909-axis)

29

mN(119910-axis)

30

mN(119911-axis)

0ndash001

(No)(Sh

)Artificialrobo

ticlim

bs(i)

Measure

norm

aland

shearforce

distr

ibution

(i)Non

unifo

rmgap

betweenelectro

des

2006

Takaoetal[7]

Piezoresistive6times6

Silicon

05ndash1V

N(N

o)0021ndash0176(N

o)Tactile

images

ensor

(rob

oticfin

gertip)

(i)Highspatial

resolutio

n(042m

m)

(ii)L

arge

scales

ensin

garray

(i)Com

plex

desig

n

2005

Shan

etal[21]


Elastic

rubb

er228m

VN

(No)

34mVN

(Sh)

0ndash2(N

o)Non

planar

surfa

ces

(tactile

sensor

skin)

(i)Detect

three-dimensio

nalforce

(ii)G

oodflexibilityand

tapedon

nonp

lanar

surfa

ce

(i)Largea

reas

kinwith

lowdensity

ofreceptors

2000

Kane

etal[8]


Polysilicon

159m

VK

Pa(N

o)032

mVK

Pa(Sh)

0ndash35

KPa(

No)

0ndash60

KPa(

Sh)

Tactile

imagingand

perceptio

n(rob

otic

application)

(i)Highresolutio

nshear

andno

rmalforce

(ii)S

tress

(i)Sensor

arrayishigh

(64times64)

(ii)N

eedcomplex

signal

cond

ition

circuit

1997

Reyetal[10]

Capacitiv

e128times128

Silicon

03bars(N

o)mdash

Fingerprint

recogn

ition

(sensora

pplication)

(i)Lo

wcost

(ii)S

implec

onstr

uctio

n

(i)Lo

wresolutio

n(005m

m)

(ii)M

easure

norm

alforceo

nly

1992

Fiorillo[22]

Ultrason

icmdash

Ferroelectric

polymer

3mm

(No)

mdashRo

botic

gripper

(i)Operateathigh

erfre

quencies

(i)Lo

wresolutio

n(lt3m

m)

(ii)A

bsorptionof

the

ultrason

icsig

nalinair

Nono

rmalforceSh

shear

force


Flexible substrate

Flexible substrate

Dielectric spacer

Adhesive

Adhesive

Resistive ink and silv

er traces

Silver conductor

Figure 7 Components of FlexiForce sensor [30]

v v

Figure 8 The behaviour of piezoelectric disk based on pressureforces [30]

ceramic lead zirconate titanate (PZT) polymer polyvinyli-dene fluoride (PVDF) and so forth are suitable for dynamictactile sensing Although quartz and ceramic PZT have betterpiezoelectric properties the polymer PVDF ismore preferredin touch sensors because of their excellent features includingmechanical flexibility high piezoelectric coefficients dimen-sional stability low weight workability chemical stabilityand chemical inertness [46ndash48] The first time PVDF wasimplemented for tactile sensing technology was reported in[49] and recently it was used for environment perceptionas discussed in [50] Henceforth to design the circuit ofpiezoelectric sensor an ultrathin input impedance is neededas a considerable effect on response to the device Figure 8illustrates that a piezoelectric disk generates a voltage whendeformed

33 Capacitive Pressure Sensor Capacitive sensors consistof a plate capacitor in which the distance between theplates or electrode area is changed when compressed and ithas a suspended structure that can measure the change in

Pressure

d

Figure 9 Capacitive sensor with two parallel plates [30]

the capacitance between these two electrodes For parallelplate capacitors capacitance can be expressed as follows

119862 =120576119900119870119860

119889 (3)

where 119862 is the capacitance 120576119900 is the relative permittivityof free space constant 119870 is the dielectric constant of thematerial in the gap 119860 is the area of the plates and 119889 isthe distance between the plates Capacitive tactile pressuresensing is considered as one of the most sensitive techniquesfor detecting small deflections of structures [51] It has beendeveloped by researchers for many years due to its featureshaving high spatial resolution good frequency response lowpower consumption and a large dynamic range [45] A capac-itor sensor array is introduced in [52] and fabricated directlyon flexible thin films of polyamide with thickness 25120583mThesensors show a linear response to applied pressure Also fewinstances of capacitive touch sensors are presented in [53]Subsequently an 8 times 8 capacitive tactile sensing array withspatial resolution at least 10 times better than the human limitof 1mm is reported in [54] Two electrodes with air gap 119889 areshown in Figure 9

As summarised there is no ideal pressure sensor technol-ogy that can be used in all applications since each has specificadvantages and constraints As a matter of fact the pressuresensor design is primarily determined by the applicationrequirements It is not just the pressure sensor technologythat is vital but also the practicalities of its implementation ofthe pressure sensor design must be considered Furthermorea wide variety of materials and technologies has been usedfor the pressure sensor resulting in performance versus costtradeoffs The electrical output signal also provides a varietyof choices for various applications

4 Robotic Hand Applications

As we know the human hand is one of the most importantparts in a body as it can arrive at narrow places and canexecute complex operations Hence it is essential for usto have a robotic hand which can accomplish the sameprocedure as a human hand does in real time Back in thedays the abilities of humanoid robots focused on walkingOnly just some robotic hands have been developed andthere has been a mounting interest in supplying them with


Figure 10 Robotic hand with tactile sensor [33]

proceedingmanipulation capabilities [55ndash58] Robotic handshave a lot of technologies to execute depending on therequired applications in some instances picking and sortingcookies [59] military robots [60] welding robots [61] andalso nuclear industry robots [62] Likewise robotic hands canalso be found in various fields such as manufacturing indus-try military space exploration domestic transportation andmedical applications

In this context manipulation capabilities are one of therobotic hand applications that are central to a robot systemFigure 10 shows an example using commercial productsa robotic hand with tactile sensors from Pressure ProfileSystems Inc (PPS) This tactile sensing technology givesthe robotic hand the ability to manipulate delicate objectswithout breaking them Moreover they will also be able tooperate at optimized low powers for energy efficiency byusing minimized grasp force Robotic platform using capaci-tive sensors is also produced by Pressure Profile Systems Incand it is described in [63]

Next optical three-axis tactile sensors are shown inFigure 11 It is used to improve sensitization quality inrobotic hand system [64] The arm actuators use the tactileinformation as feedback to execute and request the orders asneeded

41 Tactile Transduction Techniques and Applications Tactilepressure sensor has beenmulled over to be one of the suitablepressure sensors that allow humans to execute dexterousmanipulation and offer robot manipulators (handsfingers)with accurate information on the objects to grab hold andhandle Dexterous robotic hands have been developed for thepurpose of grasping different objects and it is very challengingfor many researchers [65 66] Over the years the changefrom structured to unstructured environments has made thedevelopment of different sensors a priority to enable robots tocope with considerable uncertainties Because of that sensorsthat can get back tactile information have been developed inorder to prepare robot hands with such a sense [67]

Figure 11 Optical three-axis tactile sensor [64]

There are many tactile pressure sensors that are based ona variety of principles such as resistive capacitive opticalultrasonic magnetic piezoresistive or piezoelectric sensorsUp to date a lot of tactile pressure sensors have beendeveloped Some of these works classified on the basis ofsensitivity range of pressure type of force and resolutionare given in Table 2 From 1992 to 2013 as viewed in Table 2methods miscellaneous technologies with various types ofmaterials have been used to sense the pressure in a widerange of applications particularly in robotic handDuring thetime the size of the sensor design becomes small and delicateIn comparison an array of 64 times 64 elements was used intactile imaging and perception with piezoresistive transducerin 2000 as shown in Table 2 On the other hand after decadeof time technology would have the potential to support thedevelopment ofmore intelligent products in order to improvethe quality of human life as in 2012 In this year manyresearchers involve their products to achieve what human lifeneeded a good example is a 4 times 4 array small in size andconformable using the same transducer method comparingwith previous example but in a different type of materialwhich is conductive rubber Additionally tactile pressuresensor can measure both normal and shear forces producedthrough dexterous manipulation [68 69] However most ofexisting tactile sensors only detect the normal contact forceduring handling objects in a robotic hand manipulationHence the measure of shear force is as important as a normalforce to emulate the human hand which can simultaneouslysense the direction and the strength of the applied forcewithin sophisticated manipulation Likewise measure of themechanical contact forces allows controlling the grasp forcewhich is essential for manipulator displacement and slipmovementsThis slip detection between fingertip and objectsis still one of the main issues that researchers dedicated theirtime to put an optimal solution to In fact thismatter requiredanalysing and measuring both shear and normal forces Forthis reason shear information is considered of great impor-tance to full grasp force and torque determination especiallywhen the pressure does not exceed more than 01 N [4]


These parameters will be used to predict and determineslipping of the object

42 Pick and Place Applications Robotic hands are widelyused in manufacturing industry Typically it is used forpick and place robot (such as packaging and palletizing)Pick and place process requires the use of robotic handsin order to manipulate objects In this field robotic handshave to be programmed in a familiar environment to avoidprobable conflict between tools and objects The agriculturalrobotic hand is also considered to be a good example toease up a farmerrsquos job in cutting grass [70] This robotwhich contains a manipulator a visual sensor a travellingdevice and end-effectors is able to do a number of tasksby changing the end-effectors Painting robotic is providedwith a door handler of the arm for opening and closing avehicle door before and after painting it [71] Furthermorethis system provides a robot for automatic painting vehiclebodies and reduces the equipmentrsquos cost by performing theoperations of painting vehicle bodies by itself Similarly arobot laser welding system is a robot system that consists ofa servocontrolled multiaxis mechanical hand with a lasercutting head mounted to the faceplate of the robotic handThe cutting head has focused optics for the laser light andan integral height control mechanism Most systems use alaser generator that conveys the laser light to the robot cuttinghead through an optical fiber cable The benefits of laserwelding are that it will produce higher productivity improvedflexibility and quality welds [72 73] All of existing appli-cations used a robotic hand which are equipped by diversekinds of sensors to carry through the tasks as necessitatedAs a consequence these missions cannot be accomplished asrequiredwithout algorithm since it will be as a framework forthe mechanism of robotic hand Likewise high performanceand safe operating will occur within this algorithm

43 Control Algorithm From recent development it is tracedthatmanipulation control is important for a robotManipula-tion control requires some kind of feedback which could pro-vide information about the interaction between the gripperand the grasp objects This feedback information can be usedto implement an algorithm control to achieve the functionoperator of any robotic hand application as required It hasalso been reported that multifingered robotic hand executesparticular tasks of grasping an object which needs to controlthe measuring required forces for successful operation anddexterous gripper In addition it can grasp various objectsby changing its shape Nonetheless in many cases theylack linearity or sensitivity especially in terms of masterfulgripper [74] The robotic hand gripper can increase thesensitivity as well as linearity by using an intelligent feedbackcontrol which will be doing the mechanism of gripper objecteffectively To wrap up everything various robotic handapplications using the different algorithm control had beendiscussed based on tactile sensing capabilities to increaseaccuracy flexibility and receptivity Moreover in futurerobotic hand applications the manipulators will have to bemade lighter and move faster with higher accuracy and work

Figure 12 The Shadow Dextrous Robot Hand [77]

independently For instance the automation of complex tasksin industrial applications would be highly enhanced if robotscould operate at high speed with high accuracy Neverthelessthe current robot designs are mademassive in size in order toincrease rigidity thereupon these aims cannot be executedTo achieve high speed operation and faster response forrobotic hands manipulations we should reduce the drivingtorque requirement For this purpose many one-arm flexiblerobot arms have been built in laboratories [75 76] TheShadow Dextrous Robot Hand in Figure 12 is an advancedhumanoid robot hand system available for purchase and isregarded as one of the most advanced robot hands in thecurrent world

In a nutshell various factors play an important role inachieving the appropriate application as necessitated includ-ing material type transduction method and conditioningcircuit These factors set the limitation of every applicationas viewed in Table 2 For instance the polymer (polyimide)utilized in the tactile pressure sensor fabrication is usedfor dexterous robotic manipulation applications such asgrasping objects due to it is advantages which are flexible aswell as robust enough to withstand forces during graspingDifferently the silicon MEMS technology used in a tactileimage and recognition in robotic applications requires lessflexibility but needs high spatial resolution and sensitivityHence the major application of polymer can be applied inwide area tactile sensor like artificial skin and nonplanarsurface considered to be having lower fabrication cost thansilicon Moreover silicon MEMS also reduces the number ofelectronic signalwireswhichmake it suitable for fingertip andimage recognition applications that need high resolution andalso suitable for flat surface

Beside this the best choice of transduction method andconditioning circuit is very important as they set the limit ofpower consumption time response and number of sensorsallowed to be used in an array Yet although piezoresistivesensors are commonly sensitive and economic they stillconsume a lot of power rather than others In additionthey are suitable for detecting dynamic force but have alimitation in the robotic hand application due to voltage


output decreases over time and large internal resistancewhich make them not able to measure a static force

5 Conclusion

In this paper different techniques of pressure sensor typeshave been reviewed including load cell pressure indicatingfilm and tactile pressure mapping system Similarly varioustransactionmethods including piezoresistive capacitive andpiezoelectric are discussed Tactile pressure sensor basedon piezoresistive material for robotic hand application isalso presented Different materials are used to sense thepressure in many applications including conductive rubberelastic cantilevers swollen silicon elastic rubber polysiliconferroelectric and polymer Recently piezoresistive methodswere used for robotic designed especially on grasping objectsIt was defined that the advantages were due to making useof polymers which are more flexible linear and stretchableTherefore it was found that the risk process to workers wasreduced and increased safety between the robotic hand andthe object during the interaction process

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This researchwas supported by a Science Fund grant from theMalaysian Ministry of Science Technology and Innovationand Grant Putra from the Universiti Putra Malaysia

References

[1] G Song H Wang J Zhang and T Meng ldquoAutomatic dockingsystem for recharging home surveillance robotsrdquo IEEE Transac-tions on Consumer Electronics vol 57 no 2 pp 428ndash435 2011

[2] L Zollo S Roccella E Guglielmelli M C Carrozza and PDario ldquoBiomechatronic design and control of an anthropo-morphic artificial hand for prosthetic and robotic applicationsrdquoIEEEASME Transactions on Mechatronics vol 12 no 4 pp418ndash429 2007

[3] A Rodriguez M T Mason and S S Srinivasa ldquoManipulationcapabilities with simple handsrdquo inExperimental Robotics vol 79of Springer Tracts in Advanced Robotics pp 285ndash299 SpringerBerlin Germany 2014

[4] W-C Choi ldquoPolymer micromachined flexible tactile sensorfor three-axial loads detectionrdquo Transactions on Electrical andElectronic Materials vol 11 no 3 pp 130ndash133 2010

[5] E L Lawrence I Fassola S Dayanidhi C Leclercq and FJ Valero-Cuevas ldquoAn evaluation of clustering techniques toclassify dexterousmanipulation of individuals with andwithoutdysfunctionrdquo inProceedings of the 6th International IEEEEMBSConference on Neural Engineering (NER rsquo13) pp 1254ndash1257November 2013

[6] M Florek-Jasinska T Wimbock and C Ott ldquoHumanoidcompliant whole arm dexterous manipulation control designand experimentsrdquo in Proceedings of the IEEERSJ International

Conference on Intelligent Robots and Systems (IROS rsquo14) pp1616ndash1621 Chicago Ill USA September 2014

[7] H Takao K Sawada and M Ishida ldquoMonolithic siliconsmart tactile image sensor with integrated strain sensor arrayon pneumatically swollen single-diaphragm structurerdquo IEEETransactions on Electron Devices vol 53 no 5 pp 1250ndash12592006

[8] B J KaneMRCutkosky andGTAKovacs ldquoA traction stresssensor array for use in high-resolution robotic tactile imagingrdquoJournal ofMicroelectromechanical Systems vol 9 no 4 pp 425ndash434 2000

[9] H-K Lee J Chung S-I Chang and E Yoon ldquoNormal andshear force measurement using a flexible polymer tactile sensorwith embedded multiple capacitorsrdquo Journal of Microelectrome-chanical Systems vol 17 no 4 pp 934ndash942 2008

[10] P Rey P Charvet M T Delaye and S A Hassan ldquoHighdensity capacitive pressure sensor array for fingerprint sensorapplicationrdquo in Proceedings of the International Conference onSolid-State Sensors and Actuators pp 1453ndash1456 Chicago IllUSA June 1997

[11] S Hirose and Y Umetani ldquoThe development of soft gripper forthe versatile robot handrdquoMechanism and Machine Theory vol13 no 3 pp 351ndash359 1978

[12] V Lippiello F Ruggiero B Siciliano and L Villani ldquoVisualgrasp planning for unknown objects using a multifingeredrobotic handrdquo IEEEASME Transactions on Mechatronics vol18 no 3 pp 1050ndash1059 2013

[13] F Suarez-Ruiz I Galiana Y Tenzer L P Jentoft R D HoweandM Ferre ldquoGrasp mapping between a 3-finger haptic deviceand a robotic handrdquo inHaptics Neuroscience DevicesModelingand Applications Lecture Notes in Computer Science pp 275ndash283 Springer Berlin Germany 2014

[14] RHCushman andC LHoegermeyer ldquoVacuumpick andplacerobotic handrdquo Google Patents 1985

[15] Y Zhang B K Chen X Liu and Y Sun ldquoAutonomous roboticpick-and-place ofmicroobjectsrdquo IEEE Transactions on Roboticsvol 26 no 1 pp 200ndash207 2010

[16] M H Lee and H R Nicholls ldquoReview Article Tactile sensingfor mechatronicsmdasha state of the art surveyrdquo Mechatronics vol9 no 1 pp 1ndash31 1999

[17] R S Dahiya and M Valle ldquoTactile sensing for robotic applica-tionsrdquo in Sensors Focus on Tactile Force and Stress Sensors pp289ndash304 InTech 2008

[18] M Asadnia A G P Kottapalli Z Shen J Miao and MTriantafyllou ldquoFlexible and surface-mountable piezoelectricsensor arrays for underwater sensing in marine vehiclesrdquo IEEESensors Journal vol 13 no 10 pp 3918ndash3925 2013

[19] AAqilahA Jaffar S Bahari C Y Low andTKoch ldquoResistivitycharacteristics of single miniature tactile sensing element basedon pressure sensitive conductive rubber sheetrdquo in Proceedings ofthe IEEE 8th International Colloquium on Signal Processing andIts Applications (CSPA rsquo12) pp 223ndash227 March 2012

[20] K Noda Y Hashimoto Y Tanaka and I Shimoyama ldquoMEMSon robot applicationsrdquo in Proceedings of the International Solid-State Sensors Actuators and Microsystems Conference (TRANS-DUCERS rsquo09) pp 2176ndash2181 Denver Colo USA June 2009

[21] J H Shan T Mei L Sun L Ni M Meng and J R ChuldquoThe design and fabrication of a flexible three-dimensionalforce sensor skinrdquo in Proceedings of the IEEERSJ InternationalConference on Intelligent Robots and Systems (IROS rsquo05) pp1818ndash1823 August 2005


[22] A S Fiorillo ldquoDesign and characterization of a PVDF ultra-sonic range sensorrdquo IEEE Transactions on Ultrasonics Ferro-electrics and Frequency Control vol 39 no 6 pp 688ndash692 1992

[23] I Muller R de Brito C E Pereira and V Brusamarello ldquoLoadcells in force sensing analysismdashtheory and a novel applicationrdquoIEEE Instrumentation and Measurement Magazine vol 13 no1 pp 15ndash19 2010

[24] Y Sun B J Nelson D P Potasek and E Enikov ldquoA bulkmicrofabricatedmulti-axis capacitive cellular force sensor usingtransverse comb drivesrdquo Journal of Micromechanics and Micro-engineering vol 12 no 6 pp 832ndash840 2002

[25] J Brugger M Despont C Rossel H Rothuizen P VettigerandMWillemin ldquoMicrofabricated ultrasensitive piezoresistivecantilevers for torque magnetometryrdquo Sensors and Actuators APhysical vol 73 no 3 pp 235ndash242 1999

[26] W L Tin and C D Mote Jr ldquoDevelopment and calibration ofa sub-millimeter three-component force sensorrdquo Sensors andActuators A Physical vol 65 no 1 pp 89ndash94 1998

[27] S Butefisch S Buttgenbach T Kleine-Besten and U BrandldquoMicromechanical three-axial tactile force sensor for microma-terial characterisationrdquo Microsystem Technologies vol 7 no 4pp 171ndash174 2001

[28] F Beyeler S Muntwyler Z NagyMMoser and B J Nelson ldquoAmulti-axis MEMS force-torque sensor for measuring the loadon a microrobot actuated by magnetic fieldsrdquo in Proceedingsof the IEEERSJ International Conference on Intelligent Robotsand Systems (IROS rsquo07) pp 3803ndash3808 San Diego Calif USANovember 2007

[29] J L Tan J Tien D M Pirone D S Gray K Bhadriraju and CS Chen ldquoCells lying on a bed of microneedles an approach toisolate mechanical forcerdquo Proceedings of the National Academyof Sciences of the United States of America vol 100 no 4 pp1484ndash1489 2003

[30] Tekscan ldquoFlexiForce Force Sensorsrdquo September 2014httpwwwtekscancominterface-pressure-measurement-options

[31] J I Bae T H An Y S Kim and C K Ryu ldquoAnalysis of digitalload cell using 24GHz bandrsquos Zig-Beerdquo in Proceedings of the3rd IEEE Conference on Industrial Electronics and Applications(ICIEA rsquo08) pp 1358ndash1361 June 2008

[32] E D Orth ldquoSemiconductor strain gage pressure transducerrdquoGoogle Patents 1972

[33] P S Girao P M P Ramos O Postolache and J M D PereiraldquoTactile sensors for robotic applicationsrdquoMeasurement vol 46no 3 pp 1257ndash1271 2013

[34] D E Gyi J M Porter and N K B Robertson ldquoSeat pressuremeasurement technologies considerations for their evaluationrdquoApplied Ergonomics vol 29 no 2 pp 85ndash91 1998

[35] X Wu S Rakheja and P-E Boileau ldquoDistribution of human-seat interface pressure on a soft automotive seat under verticalvibrationrdquo International Journal of Industrial Ergonomics vol24 no 5 pp 545ndash557 1999

[36] F Khoshnoud and C W de Silva ldquoRecent advances in MEMSsensor technology-biomedical applicationsrdquo IEEE Instrumenta-tion and Measurement Magazine vol 15 no 1 pp 8ndash14 2012

[37] H Zhang and E So ldquoHybrid resistive tactile sensingrdquo IEEETransactions on Systems Man and Cybernetics Part B Cyber-netics vol 32 no 1 pp 57ndash65 2002

[38] KWeiszlig andHWorn ldquoTheworking principle of resistive tactilesensor cellsrdquo in Proceedings of the IEEE International Conferenceon Mechatronics and Automation pp 471ndash476 2005

[39] A M M Almassri W Z W Hasan S A Ahmad and A JIshak ldquoA sensitivity study of piezoresistive pressure sensor forrobotic handrdquo inProceedings of the IEEERegional SymposiumonMicro and Nano Electronics (RSM rsquo13) pp 394ndash397 LangkawiMalaysia September 2013

[40] CM A Ashruf ldquoThin flexible pressure sensorsrdquo Sensor Reviewvol 22 no 4 pp 322ndash327 2002

[41] G S Gupta S C Mukhopadhyay C H Messom and S NDemidenko ldquoMaster-slave control of a teleoperated anthro-pomorphic robotic arm with gripping force sensingrdquo IEEETransactions on Instrumentation and Measurement vol 55 no6 pp 2136ndash2145 2006

[42] M Ferguson-Pell S Hagisawa and D Bain ldquoEvaluation of asensor for low interface pressure applicationsrdquo Medical Engi-neering and Physics vol 22 no 9 pp 657ndash663 2000

[43] C Steinem A Janshoff andM A Cooper Piezoelectric SensorsSpringer New York NY USA 2007

[44] P Puangmali K Althoefer L D Seneviratne D Murphy andP Dasgupta ldquoState-of-the-art in force and tactile sensing forminimally invasive surgeryrdquo IEEE Sensors Journal vol 8 no 4pp 371ndash380 2008

[45] M I Tiwana S J Redmond and N H Lovell ldquoA review oftactile sensing technologies with applications in biomedicalengineeringrdquo Sensors and Actuators A Physical vol 179 pp 17ndash31 2012

[46] J R Flanagan and A M Wing ldquoModulation of grip force withload force during point-to-point arm movementsrdquo Experimen-tal Brain Research vol 95 no 1 pp 131ndash143 1993

[47] S B Lang and S Muensit ldquoReview of some lesser-known appli-cations of piezoelectric and pyroelectric polymersrdquo AppliedPhysics A vol 85 no 2 pp 125ndash134 2006

[48] A Song Y HanHHu and J Li ldquoA novel texture sensor for fab-ric texture measurement and classificationrdquo IEEE Transactionson Instrumentation and Measurement vol 63 no 7 pp 1739ndash1747 2013

[49] P Dario and D De Rossi ldquoTactile sensors and the grippingchallenge increasing the performance of sensors over a widerange of force is a first step toward robotry that can hold andmanipulate objects as humans dordquo IEEE Spectrum vol 22 no8 pp 46ndash53 1985

[50] A Song Y Han H Hu L Tian and J Wu ldquoActive perception-based haptic texture sensorrdquo Sensors and Materials vol 25 no1 pp 1ndash15 2013

[51] V Maheshwari and R Saraf ldquoTactile devices to sense touch ona par with a human fingerrdquo Angewandte Chemie InternationalEdition vol 47 no 41 pp 7808ndash7826 2008

[52] E Pritchard M Mahfouz B Evans S Eliza and M HaiderldquoFlexible capacitive sensors for high resolution pressure mea-surementrdquo in Proceedings of the Sensors Conference pp 1484ndash1487 Lecce Italy 2008

[53] P A Schmidt E Mael and R P Wurtz ldquoA sensor fordynamic tactile information with applications in human-robotinteraction and object explorationrdquo Robotics and AutonomousSystems vol 54 no 12 pp 1005ndash1014 2006

[54] B L Gray and R S Fearing ldquoA surface micromachinedmicrotactile sensor arrayrdquo in Proceedings of the IEEE Interna-tional Conference on Robotics and Automation vol 1 pp 1ndash6Minneapolis Minn USA April 1996

[55] S Jacobsen E Iversen D Knutti R Johnson and K BiggersldquoDesign of the UtahMIT dextrous handrdquo in Proceedings of theIEEE International Conference on Robotics and Automation pp1520ndash1532 April 1986


[56] F Lotti P Tiezzi G Vassura L Biagiotti and C MelchiorrildquoUBH 3 an anthropomorphic hand with simplified endo-skeletal structure and soft continuous fingerpadsrdquo in Proceed-ings of the IEEE International Conference on Robotics andAutomation (ICRA rsquo04) pp 4736ndash4741 May 2004

[57] J Butterfaszlig M Grebenstein H Liu and G Hirzinger ldquoDLR-Hand II next generation of a dextrous robot handrdquo in Pro-ceedings of the IEEE International Conference on Robotics andAutomation (ICRA rsquo01) pp 109ndash114 2001

[58] A Kargov T Asfour C Pylatiuk et al ldquoDevelopment of ananthropomorphic hand for amobile assistive robotrdquo in Proceed-ings of the IEEE 9th International Conference on RehabilitationRobotics (ICORR rsquo05) pp 182ndash186 Chicago Ill USA July 2005

[59] C Jones G Ross J R Hewit and A P Slade ldquoRobotic sortingof paper items from a random pilerdquoMechatronics vol 10 no 8pp 869ndash880 2000

[60] Y Ma Z Cao X Dong C Zhou and M Tan ldquoA multi-robot coordinated hunting strategy with dynamic alliancerdquo inProceedings of the Chinese Control and Decision Conference(CCDC rsquo09) pp 2338ndash2342 June 2009

[61] A Ryberg M Ericsson A-K Christiansson K Eriksson JNilsson and M Larsson ldquoStereo vision for path correction inoff-line programmed robot weldingrdquo in Proceedings of the IEEEInternational Conference on Industrial Technology (ICIT rsquo10) pp1700ndash1705 March 2010

[62] M Ali R Puffer and H Roman ldquoEvaluation of a multifingeredrobot hand for nuclear power plant operations andmaintenancetasksrdquo Tech Rep Society of Manufacturing Engineers 1994

[63] J M Romano K Hsiao G Niemeyer S Chitta and K JKuchenbecker ldquoHuman-inspired robotic grasp control withtactile sensingrdquo IEEE Transactions on Robotics vol 27 no 6 pp1067ndash1079 2011

[64] H Yussof JWada andMOhka ldquoSensorization of robotic handusing optical three-axis tactile sensor evaluation with graspingand twisting motionsrdquo Journal of Computer Science vol 6 no8 pp 955ndash962 2010

[65] M T Mason and J K Salisbury Jr Robot Hands and theMechanics of Manipulation 1985

[66] M T Ciocarlie and P K Allen ldquoHand posture subspaces fordexterous robotic graspingrdquo International Journal of RoboticsResearch vol 28 no 7 pp 851ndash867 2009

[67] R S Dahiya G Metta M Valle and G Sandini ldquoTactilesensingmdashfrom humans to humanoidsrdquo IEEE Transactions onRobotics vol 26 no 1 pp 1ndash20 2010

[68] K Kim K R Lee Y K Kim et al ldquo3-Axes flexible tactile sensorfabricated by SI micromachining and packaging technologyrdquo inProceedings of the 19th IEEE International Conference on MicroElectro Mechanical Systems (MEMS rsquo06) pp 678ndash681 IstanbulTurky January 2006

[69] T-R Hsu MEMS amp Microsystems Design Manufacture andNanoscale Engineering JohnWileyamp Sons NewYork NYUSA2008

[70] M Monta N Kondo and Y Shibano ldquoAgricultural robot ingrape production systemrdquo in Proceedings of the IEEE Interna-tional Conference on Robotics and Automation pp 2504ndash2509May 1995

[71] H Kiba Y Itoh and K Kiryu ldquoVehicle body painting robotrdquoGoogle Patents 1985

[72] H-S Kang J Suh and S J Kwak ldquoWelding on the fly by usinglaser scanner and robotrdquo in Proceedings of the 11th InternationalConference on Control Automation and Systems (ICCAS rsquo11) pp1688ndash1691 October 2011

[73] H-S Kang J Suh and T-D Cho ldquoStudy on robot applicationtechnology for laser weldingrdquo in Proceedings of the InternationalConference on Smart Manufacturing Application (ICSMA rsquo08)pp 354ndash356 Gyeonggi-do Republic of Korea April 2008

[74] J G Webster Tactile Sensors for Robotics and Medicine JohnWiley amp Sons New York NY USA 1988

[75] R H Cannon Jr and E Schmitz ldquoInitial experiments on theend-point control of a flexible one-link robotrdquoThe InternationalJournal of Robotics Research vol 3 no 3 pp 62ndash75 1984

[76] G G Hastings andW J Book ldquoVerification of a linear dynamicmodel for flexible robotic manipulatorsrdquo in Proceedings of theIEEE International Conference on Robotics and Automation pp1024ndash1029 1986

[77] A Bernardino M Henriques N Hendrich and J ZhangldquoPrecision grasp synergies for dexterous robotic handsrdquo inProceedings of the IEEE International Conference onRobotics andBiomimetics (ROBIO rsquo13) pp 62ndash67 December 2013

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Active and Passive Electronic Components

Control Scienceand Engineering

Journal of



RotatingMachinery


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

Acoustics and VibrationAdvances in



Electrical and Computer Engineering

Journal of

Advances inOptoElectronics


Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks



load cells pressure indicating film and tactile pressuresystem Similarly a review on industry pressure sensingthat involves the pick and place applications and algorithmcontrol is also highlighted The paper also discusses theMEMS sensor technology and different types of sensorswhile the last section of this part discusses the piezoresistiveflexiForce sensor FlexiForce sensor has a good substratematerial which is a polymer that enhances the force sensingand improves the performance of force linearity hysteresisdrift and temperature sensitivity compared to any other thinfilm Furthermore it is flexible and ultrathin enough as theresearchers and designers can use it in different integratedapplications as well as for applications that are orientedto manipulative tasks with grippers of robotic hand In anutshell new applications for tactile pressure sensing show ahigh increase in publications and research attention as viewedin Table 2 As a result the design of sensor becomes moreprecise with higher reliability to overcome the problems

2 Sense of Pressure Methods

Pressure is force per unit area applied in a direction perpen-dicular to the surface of an object The formula is commonlywritten as follows

119875 =119865

119860 (1)

where 119875 is the pressure 119865 is the normal force and 119860 isthe area of the surface of contact When two objects arecontacted they exert force on each other Thus the averageinterface pressure is the total force divided by the interfaceregion In contrast pressure measurement is necessary to geta peak pressure when the interface pressure is not uniformlydistributed In this context there are three technologies andmethods to be considered to measure force or interfacepressures load cells pressure indicating film and tactilepressure sensor

21 Load Cell Load cell is a type of pressure sensor which iscommonly used in industrial weighing product to measureforce such as goods and vehicles The gripper of a robotichand that picks up an object can be equipped with loadcells in order to provide compression force feedback tothe control system which prevents damage to the object orreleased too early Also load cells can be used to measure thecompression forces during a robot walk to provide data forthe equilibrium-controlling system In industrial machineryrods beams wheels and bars are instrumented in orderto control the forces exerted on them Due to this varietyof possible applications load cells are very important [23]There are many types of technologies which are used tomeasure loads such as strain gauges piezoelectric elementsand variable capacitance

Moreover depending on the applied force andmechanicsof application multiple form factors of load cells are utilizedTypically multiaxis MEMS force-torque sensors are usedto measure the load In the literature a small numberof multiaxis MEMS sensors have been reported In [24]

LCLC

LC LC

Figure 1 Pressure measurement using multiple load cells [30]

a capacitiveMEMS force sensor is presented which assess theforce along two axes In [25 26] the design of a piezoresistivethree-axis force sensor is described A piezoresistive torquesensor has been presented in [27] In addition a three-axiscapacitive MEMS force-torque sensor has been reported in[28] and this sensor is able to measure forces along two axesand a torque perpendicular to these forces Aswe know forcescan be sensed in a plane while a torque perpendicular to thisplane can bemeasured In certain conditions researchers canusemultiple load cells tomeasure forces overmultiple regionsof a contact interface [29] In Figure 1 an interface or contactarea is divided into four quadrants with an exclusive loadcell measuring each area This arrangement provides moredetails on the force distribution across the surface the averagepressure in each zone will occur Still the disadvantage of thistechnique is inconsistent because the load cell can show thetotal force but cannot identify localized spikes in pressureThere are many different types of load cells that operate indifferent ways but currently the most commonly used loadcell is the strain gage (or strain gauge) load cell

211 Strain Gauge Load Cells Strain gages are small patchesof silicone or metal that measure mechanical strain andconvert the load acting to electrical signals This load cell isconsidered as an analog type tool and utilized to measureweight When a load is applied to a stationary object stressand strain are the result Stress is defined as the objectrsquosinternal resisting forces and strain is the displacement anddisfigurement that occurs [31] so the load causes deforma-tions in the material or object that can be measured usingstrain gauges Two capacitive pressure gauges which havebeen used extensively in the study of liquid and solid heliumare described [32] Figure 2 illustrates a structure of straingauges Here more resistance in strain gauge will increasethe stability as seen in Figure 2 In fact it also offers a widerange of different patterns which means various applicationswill occur

22 Pressure Indicating Film Pressure indicating film iswidely used to measure interface pressures between two


Gauge length

Strainresistor

Tab

Backing



A-film

C-film




Conductive silver


Flexible substrates









DigitaloutputAD

Control circuit

Sensor array






Ω

F





119877 =120588 times 119897

119905 times 120596 (2)








Piezoresistive






Optical





Magnetic











Table2Pressure

sensor

with

vario

usapplications

basedon

different

transductio

nmetho

ds

Year

AuthorRef

Transducer

metho

d

Array

numbero

felem

ents

Material

type

Forcepressure

sensitivityor

resolutio

n[N]

Forcepressure

sensitivityor

resolutio

nrange[

N]

Application

Limitatio

ns

Advantages

Weakn

ess

2013

Asadn

iaetal[18]


Liqu

idcrystal

polymer

3mmsminus1(N

o)mdash

Und

erwater

sensing

(auton

omou

s)

(i)Detectverylow

frequ

ency

(dow

nto

01H

z)in

water

(ii)H

ighresolutio

n(3mmsminus

1 )(iii)Self-po

wered

and

passively

sense

underw

ater

objects

(i)Ap

pliedun

derw

ater

2012

Aqilahetal[19]

Resistiv

e4times4

Con

ductive

rubb

er15kgcm

2(N

o)mdash

Robo

tichand

(i)Flexibilityand

stretchability

(ii)L

inearity

(i)Needexternalpo

wer

(ii)M

axim

umpressure

islow

2010

Choi[4]

Strain

gauge4times4

Polymer

2066m

V(N

o)701mV(Sh)

0ndash08(N

o)(Sh

)Dexterous

manipulation(rob

otic

fingertip)

(i)Measure

norm

aland

shearloads

simultaneou

sly

(i)Lo

wforcec

apacity

(06N)

2009

Nod

aetal[20]

Piezoresistive

mdashSilicon

rubb

er001(N

o)01

(Sh)

005ndash3

(No)

005ndash3

(Sh)

Dexterous

manipulation(rob

otic

application)

(i)Highsensitive

sensor

(i)Com

plex

desig

n(ii)Infl

exibility

2008

Leee

tal[9]

Capacitiv

e8times8

Polymer

25

mN(119909-axis)

29

mN(119910-axis)

30

mN(119911-axis)

0ndash001

(No)(Sh

)Artificialrobo

ticlim

bs(i)

Measure

norm

aland

shearforce

distr

ibution

(i)Non

unifo

rmgap

betweenelectro

des

2006

Takaoetal[7]


Silicon

05ndash1V

N(N

o)0021ndash0176(N

o)Tactile

images

ensor

(rob

oticfin

gertip)

(i)Highspatial

resolutio

n(042m

m)

(ii)L

arge

scales

ensin

garray

(i)Com

plex

desig

n

2005

Shan

etal[21]


Elastic

rubb

er228m

VN

(No)

34mVN

(Sh)

0ndash2(N

o)Non

planar

surfa

ces

(tactile

sensor

skin)

(i)Detect

three-dimensio

nalforce

(ii)G

oodflexibilityand

tapedon

nonp

lanar

surfa

ce

(i)Largea

reas

kinwith

lowdensity

ofreceptors

2000

Kane

etal[8]


Polysilicon

159m

VK

Pa(N

o)032

mVK

Pa(Sh)

0ndash35

KPa(

No)

0ndash60

KPa(

Sh)

Tactile

imagingand

perceptio

n(rob

otic

application)

(i)Highresolutio

nshear

andno

rmalforce

(ii)S

tress

(i)Sensor

arrayishigh

(64times64)

(ii)N

eedcomplex

signal

cond

ition

circuit

1997

Reyetal[10]

Capacitiv

e128times128

Silicon

03bars(N

o)mdash

Fingerprint

recogn

ition

(sensora

pplication)

(i)Lo

wcost

(ii)S

implec

onstr

uctio

n

(i)Lo

wresolutio

n(005m

m)

(ii)M

easure

norm

alforceo

nly

1992

Fiorillo[22]

Ultrason

icmdash

Ferroelectric

polymer

3mm

(No)

mdashRo

botic

gripper

(i)Operateathigh

erfre

quencies

(i)Lo

wresolutio

n(lt3m

m)

(ii)A

bsorptionof

the

ultrason

icsig

nalinair

Nono

rmalforceSh

shear

force


Flexible substrate

Flexible substrate

Dielectric spacer

Adhesive

Adhesive


er traces

Silver conductor


v v




Pressure

d



119862 =120576119900119870119860

119889 (3)























5 Conclusion




Acknowledgments


References



















































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Gauge length

Strainresistor

Tab

Backing



A-film

C-film




Conductive silver


Flexible substrates









DigitaloutputAD

Control circuit

Sensor array






Ω

F





119877 =120588 times 119897

119905 times 120596 (2)








Piezoresistive






Optical





Magnetic











Table2Pressure

sensor

with

vario

usapplications

basedon

different

transductio

nmetho

ds

Year

AuthorRef

Transducer

metho

d

Array

numbero

felem

ents

Material

type

Forcepressure

sensitivityor

resolutio

n[N]

Forcepressure

sensitivityor

resolutio

nrange[

N]

Application

Limitatio

ns

Advantages

Weakn

ess

2013

Asadn

iaetal[18]


Liqu

idcrystal

polymer

3mmsminus1(N

o)mdash

Und

erwater

sensing

(auton

omou

s)

(i)Detectverylow

frequ

ency

(dow

nto

01H

z)in

water

(ii)H

ighresolutio

n(3mmsminus

1 )(iii)Self-po

wered

and

passively

sense

underw

ater

objects

(i)Ap

pliedun

derw

ater

2012

Aqilahetal[19]

Resistiv

e4times4

Con

ductive

rubb

er15kgcm

2(N

o)mdash

Robo

tichand

(i)Flexibilityand

stretchability

(ii)L

inearity

(i)Needexternalpo

wer

(ii)M

axim

umpressure

islow

2010

Choi[4]

Strain

gauge4times4

Polymer

2066m

V(N

o)701mV(Sh)

0ndash08(N

o)(Sh

)Dexterous

manipulation(rob

otic

fingertip)

(i)Measure

norm

aland

shearloads

simultaneou

sly

(i)Lo

wforcec

apacity

(06N)

2009

Nod

aetal[20]

Piezoresistive

mdashSilicon

rubb

er001(N

o)01

(Sh)

005ndash3

(No)

005ndash3

(Sh)

Dexterous

manipulation(rob

otic

application)

(i)Highsensitive

sensor

(i)Com

plex

desig

n(ii)Infl

exibility

2008

Leee

tal[9]

Capacitiv

e8times8

Polymer

25

mN(119909-axis)

29

mN(119910-axis)

30

mN(119911-axis)

0ndash001

(No)(Sh

)Artificialrobo

ticlim

bs(i)

Measure

norm

aland

shearforce

distr

ibution

(i)Non

unifo

rmgap

betweenelectro

des

2006

Takaoetal[7]


Silicon

05ndash1V

N(N

o)0021ndash0176(N

o)Tactile

images

ensor

(rob

oticfin

gertip)

(i)Highspatial

resolutio

n(042m

m)

(ii)L

arge

scales

ensin

garray

(i)Com

plex

desig

n

2005

Shan

etal[21]


Elastic

rubb

er228m

VN

(No)

34mVN

(Sh)

0ndash2(N

o)Non

planar

surfa

ces

(tactile

sensor

skin)

(i)Detect

three-dimensio

nalforce

(ii)G

oodflexibilityand

tapedon

nonp

lanar

surfa

ce

(i)Largea

reas

kinwith

lowdensity

ofreceptors

2000

Kane

etal[8]


Polysilicon

159m

VK

Pa(N

o)032

mVK

Pa(Sh)

0ndash35

KPa(

No)

0ndash60

KPa(

Sh)

Tactile

imagingand

perceptio

n(rob

otic

application)

(i)Highresolutio

nshear

andno

rmalforce

(ii)S

tress

(i)Sensor

arrayishigh

(64times64)

(ii)N

eedcomplex

signal

cond

ition

circuit

1997

Reyetal[10]

Capacitiv

e128times128

Silicon

03bars(N

o)mdash

Fingerprint

recogn

ition

(sensora

pplication)

(i)Lo

wcost

(ii)S

implec

onstr

uctio

n

(i)Lo

wresolutio

n(005m

m)

(ii)M

easure

norm

alforceo

nly

1992

Fiorillo[22]

Ultrason

icmdash

Ferroelectric

polymer

3mm

(No)

mdashRo

botic

gripper

(i)Operateathigh

erfre

quencies

(i)Lo

wresolutio

n(lt3m

m)

(ii)A

bsorptionof

the

ultrason

icsig

nalinair

Nono

rmalforceSh

shear

force


Flexible substrate

Flexible substrate

Dielectric spacer

Adhesive

Adhesive


er traces

Silver conductor


v v




Pressure

d



119862 =120576119900119870119860

119889 (3)























5 Conclusion




Acknowledgments


References



















































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











DigitaloutputAD

Control circuit

Sensor array






Ω

F





119877 =120588 times 119897

119905 times 120596 (2)








Piezoresistive






Optical





Magnetic











Table2Pressure

sensor

with

vario

usapplications

basedon

different

transductio

nmetho

ds

Year

AuthorRef

Transducer

metho

d

Array

numbero

felem

ents

Material

type

Forcepressure

sensitivityor

resolutio

n[N]

Forcepressure

sensitivityor

resolutio

nrange[

N]

Application

Limitatio

ns

Advantages

Weakn

ess

2013

Asadn

iaetal[18]


Liqu

idcrystal

polymer

3mmsminus1(N

o)mdash

Und

erwater

sensing

(auton

omou

s)

(i)Detectverylow

frequ

ency

(dow

nto

01H

z)in

water

(ii)H

ighresolutio

n(3mmsminus

1 )(iii)Self-po

wered

and

passively

sense

underw

ater

objects

(i)Ap

pliedun

derw

ater

2012

Aqilahetal[19]

Resistiv

e4times4

Con

ductive

rubb

er15kgcm

2(N

o)mdash

Robo

tichand

(i)Flexibilityand

stretchability

(ii)L

inearity

(i)Needexternalpo

wer

(ii)M

axim

umpressure

islow

2010

Choi[4]

Strain

gauge4times4

Polymer

2066m

V(N

o)701mV(Sh)

0ndash08(N

o)(Sh

)Dexterous

manipulation(rob

otic

fingertip)

(i)Measure

norm

aland

shearloads

simultaneou

sly

(i)Lo

wforcec

apacity

(06N)

2009

Nod

aetal[20]

Piezoresistive

mdashSilicon

rubb

er001(N

o)01

(Sh)

005ndash3

(No)

005ndash3

(Sh)

Dexterous

manipulation(rob

otic

application)

(i)Highsensitive

sensor

(i)Com

plex

desig

n(ii)Infl

exibility

2008

Leee

tal[9]

Capacitiv

e8times8

Polymer

25

mN(119909-axis)

29

mN(119910-axis)

30

mN(119911-axis)

0ndash001

(No)(Sh

)Artificialrobo

ticlim

bs(i)

Measure

norm

aland

shearforce

distr

ibution

(i)Non

unifo

rmgap

betweenelectro

des

2006

Takaoetal[7]


Silicon

05ndash1V

N(N

o)0021ndash0176(N

o)Tactile

images

ensor

(rob

oticfin

gertip)

(i)Highspatial

resolutio

n(042m

m)

(ii)L

arge

scales

ensin

garray

(i)Com

plex

desig

n

2005

Shan

etal[21]


Elastic

rubb

er228m

VN

(No)

34mVN

(Sh)

0ndash2(N

o)Non

planar

surfa

ces

(tactile

sensor

skin)

(i)Detect

three-dimensio

nalforce

(ii)G

oodflexibilityand

tapedon

nonp

lanar

surfa

ce

(i)Largea

reas

kinwith

lowdensity

ofreceptors

2000

Kane

etal[8]


Polysilicon

159m

VK

Pa(N

o)032

mVK

Pa(Sh)

0ndash35

KPa(

No)

0ndash60

KPa(

Sh)

Tactile

imagingand

perceptio

n(rob

otic

application)

(i)Highresolutio

nshear

andno

rmalforce

(ii)S

tress

(i)Sensor

arrayishigh

(64times64)

(ii)N

eedcomplex

signal

cond

ition

circuit

1997

Reyetal[10]

Capacitiv

e128times128

Silicon

03bars(N

o)mdash

Fingerprint

recogn

ition

(sensora

pplication)

(i)Lo

wcost

(ii)S

implec

onstr

uctio

n

(i)Lo

wresolutio

n(005m

m)

(ii)M

easure

norm

alforceo

nly

1992

Fiorillo[22]

Ultrason

icmdash

Ferroelectric

polymer

3mm

(No)

mdashRo

botic

gripper

(i)Operateathigh

erfre

quencies

(i)Lo

wresolutio

n(lt3m

m)

(ii)A

bsorptionof

the

ultrason

icsig

nalinair

Nono

rmalforceSh

shear

force


Flexible substrate

Flexible substrate

Dielectric spacer

Adhesive

Adhesive


er traces

Silver conductor


v v




Pressure

d



119862 =120576119900119870119860

119889 (3)























5 Conclusion




Acknowledgments


References



















































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation














Piezoresistive






Optical





Magnetic











Table2Pressure

sensor

with

vario

usapplications

basedon

different

transductio

nmetho

ds

Year

AuthorRef

Transducer

metho

d

Array

numbero

felem

ents

Material

type

Forcepressure

sensitivityor

resolutio

n[N]

Forcepressure

sensitivityor

resolutio

nrange[

N]

Application

Limitatio

ns

Advantages

Weakn

ess

2013

Asadn

iaetal[18]


Liqu

idcrystal

polymer

3mmsminus1(N

o)mdash

Und

erwater

sensing

(auton

omou

s)

(i)Detectverylow

frequ

ency

(dow

nto

01H

z)in

water

(ii)H

ighresolutio

n(3mmsminus

1 )(iii)Self-po

wered

and

passively

sense

underw

ater

objects

(i)Ap

pliedun

derw

ater

2012

Aqilahetal[19]

Resistiv

e4times4

Con

ductive

rubb

er15kgcm

2(N

o)mdash

Robo

tichand

(i)Flexibilityand

stretchability

(ii)L

inearity

(i)Needexternalpo

wer

(ii)M

axim

umpressure

islow

2010

Choi[4]

Strain

gauge4times4

Polymer

2066m

V(N

o)701mV(Sh)

0ndash08(N

o)(Sh

)Dexterous

manipulation(rob

otic

fingertip)

(i)Measure

norm

aland

shearloads

simultaneou

sly

(i)Lo

wforcec

apacity

(06N)

2009

Nod

aetal[20]

Piezoresistive

mdashSilicon

rubb

er001(N

o)01

(Sh)

005ndash3

(No)

005ndash3

(Sh)

Dexterous

manipulation(rob

otic

application)

(i)Highsensitive

sensor

(i)Com

plex

desig

n(ii)Infl

exibility

2008

Leee

tal[9]

Capacitiv

e8times8

Polymer

25

mN(119909-axis)

29

mN(119910-axis)

30

mN(119911-axis)

0ndash001

(No)(Sh

)Artificialrobo

ticlim

bs(i)

Measure

norm

aland

shearforce

distr

ibution

(i)Non

unifo

rmgap

betweenelectro

des

2006

Takaoetal[7]


Silicon

05ndash1V

N(N

o)0021ndash0176(N

o)Tactile

images

ensor

(rob

oticfin

gertip)

(i)Highspatial

resolutio

n(042m

m)

(ii)L

arge

scales

ensin

garray

(i)Com

plex

desig

n

2005

Shan

etal[21]


Elastic

rubb

er228m

VN

(No)

34mVN

(Sh)

0ndash2(N

o)Non

planar

surfa

ces

(tactile

sensor

skin)

(i)Detect

three-dimensio

nalforce

(ii)G

oodflexibilityand

tapedon

nonp

lanar

surfa

ce

(i)Largea

reas

kinwith

lowdensity

ofreceptors

2000

Kane

etal[8]


Polysilicon

159m

VK

Pa(N

o)032

mVK

Pa(Sh)

0ndash35

KPa(

No)

0ndash60

KPa(

Sh)

Tactile

imagingand

perceptio

n(rob

otic

application)

(i)Highresolutio

nshear

andno

rmalforce

(ii)S

tress

(i)Sensor

arrayishigh

(64times64)

(ii)N

eedcomplex

signal

cond

ition

circuit

1997

Reyetal[10]

Capacitiv

e128times128

Silicon

03bars(N

o)mdash

Fingerprint

recogn

ition

(sensora

pplication)

(i)Lo

wcost

(ii)S

implec

onstr

uctio

n

(i)Lo

wresolutio

n(005m

m)

(ii)M

easure

norm

alforceo

nly

1992

Fiorillo[22]

Ultrason

icmdash

Ferroelectric

polymer

3mm

(No)

mdashRo

botic

gripper

(i)Operateathigh

erfre

quencies

(i)Lo

wresolutio

n(lt3m

m)

(ii)A

bsorptionof

the

ultrason

icsig

nalinair

Nono

rmalforceSh

shear

force


Flexible substrate

Flexible substrate

Dielectric spacer

Adhesive

Adhesive


er traces

Silver conductor


v v




Pressure

d



119862 =120576119900119870119860

119889 (3)























5 Conclusion




Acknowledgments


References



















































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table2Pressure

sensor

with

vario

usapplications

basedon

different

transductio

nmetho

ds

Year

AuthorRef

Transducer

metho

d

Array

numbero

felem

ents

Material

type

Forcepressure

sensitivityor

resolutio

n[N]

Forcepressure

sensitivityor

resolutio

nrange[

N]

Application

Limitatio

ns

Advantages

Weakn

ess

2013

Asadn

iaetal[18]


Liqu

idcrystal

polymer

3mmsminus1(N

o)mdash

Und

erwater

sensing

(auton

omou

s)

(i)Detectverylow

frequ

ency

(dow

nto

01H

z)in

water

(ii)H

ighresolutio

n(3mmsminus

1 )(iii)Self-po

wered

and

passively

sense

underw

ater

objects

(i)Ap

pliedun

derw

ater

2012

Aqilahetal[19]

Resistiv

e4times4

Con

ductive

rubb

er15kgcm

2(N

o)mdash

Robo

tichand

(i)Flexibilityand

stretchability

(ii)L

inearity

(i)Needexternalpo

wer

(ii)M

axim

umpressure

islow

2010

Choi[4]

Strain

gauge4times4

Polymer

2066m

V(N

o)701mV(Sh)

0ndash08(N

o)(Sh

)Dexterous

manipulation(rob

otic

fingertip)

(i)Measure

norm

aland

shearloads

simultaneou

sly

(i)Lo

wforcec

apacity

(06N)

2009

Nod

aetal[20]

Piezoresistive

mdashSilicon

rubb

er001(N

o)01

(Sh)

005ndash3

(No)

005ndash3

(Sh)

Dexterous

manipulation(rob

otic

application)

(i)Highsensitive

sensor

(i)Com

plex

desig

n(ii)Infl

exibility

2008

Leee

tal[9]

Capacitiv

e8times8

Polymer

25

mN(119909-axis)

29

mN(119910-axis)

30

mN(119911-axis)

0ndash001

(No)(Sh

)Artificialrobo

ticlim

bs(i)

Measure

norm

aland

shearforce

distr

ibution

(i)Non

unifo

rmgap

betweenelectro

des

2006

Takaoetal[7]


Silicon

05ndash1V

N(N

o)0021ndash0176(N

o)Tactile

images

ensor

(rob

oticfin

gertip)

(i)Highspatial

resolutio

n(042m

m)

(ii)L

arge

scales

ensin

garray

(i)Com

plex

desig

n

2005

Shan

etal[21]


Elastic

rubb

er228m

VN

(No)

34mVN

(Sh)

0ndash2(N

o)Non

planar

surfa

ces

(tactile

sensor

skin)

(i)Detect

three-dimensio

nalforce

(ii)G

oodflexibilityand

tapedon

nonp

lanar

surfa

ce

(i)Largea

reas

kinwith

lowdensity

ofreceptors

2000

Kane

etal[8]


Polysilicon

159m

VK

Pa(N

o)032

mVK

Pa(Sh)

0ndash35

KPa(

No)

0ndash60

KPa(

Sh)

Tactile

imagingand

perceptio

n(rob

otic

application)

(i)Highresolutio

nshear

andno

rmalforce

(ii)S

tress

(i)Sensor

arrayishigh

(64times64)

(ii)N

eedcomplex

signal

cond

ition

circuit

1997

Reyetal[10]

Capacitiv

e128times128

Silicon

03bars(N

o)mdash

Fingerprint

recogn

ition

(sensora

pplication)

(i)Lo

wcost

(ii)S

implec

onstr

uctio

n

(i)Lo

wresolutio

n(005m

m)

(ii)M

easure

norm

alforceo

nly

1992

Fiorillo[22]

Ultrason

icmdash

Ferroelectric

polymer

3mm

(No)

mdashRo

botic

gripper

(i)Operateathigh

erfre

quencies

(i)Lo

wresolutio

n(lt3m

m)

(ii)A

bsorptionof

the

ultrason

icsig

nalinair

Nono

rmalforceSh

shear

force


Flexible substrate

Flexible substrate

Dielectric spacer

Adhesive

Adhesive


er traces

Silver conductor


v v




Pressure

d



119862 =120576119900119870119860

119889 (3)























5 Conclusion




Acknowledgments


References



















































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Flexible substrate

Flexible substrate

Dielectric spacer

Adhesive

Adhesive


er traces

Silver conductor


v v




Pressure

d



119862 =120576119900119870119860

119889 (3)























5 Conclusion




Acknowledgments


References



















































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation



























5 Conclusion




Acknowledgments


References



















































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation



















5 Conclusion




Acknowledgments


References



















































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











5 Conclusion




Acknowledgments


References



















































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation





































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









Documents

Review Article Pressure Sensor: State of the Art, Design ...downloads.hindawi.com/journals/js/2015/846487.pdf · Journal of Sensors load cells, pressure indicating lm, and tactile