Nano/Micro-Electro-Mechanical Systems for Sensor Applications: A Brief Review

This article was downloaded by: [Northeastern University]On: 20 November 2014, At: 16:41Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,37-41 Mortimer Street, London W1T 3JH, UK

IETE Journal of EducationPublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/tije20

Nano/Micro-Electro-Mechanical Systems for SensorApplications: A Brief ReviewV. Subrahmanyama, P.S.S. Narayana Raoa, D.V. Ramamurthyb & P.C. Krishnamacharyc

a Associate Professor, Ideal Institute of Technology, Kakinadab Principal, Ideal Institute of Technology, Kakinadac Principal, Sree Vidyanikethan Engineering College, Sree Sainath Nagar, A. Rangampet 517102, Chittoor District, AP, e-mail:Published online: 01 Sep 2014.

To cite this article: V. Subrahmanyam, P.S.S. Narayana Rao, D.V. Ramamurthy & P.C. Krishnamachary (2010) Nano/Micro-Electro-Mechanical Systems for Sensor Applications: A Brief Review, IETE Journal of Education, 51:1, 23-31, DOI:10.1080/09747338.2010.10876065

To link to this article: http://dx.doi.org/10.1080/09747338.2010.10876065

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) containedin the publications on our platform. However, Taylor & Francis, our agents, and our licensors make norepresentations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of theContent. Any opinions and views expressed in this publication are the opinions and views of the authors, andare not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon andshould be independently verified with primary sources of information. Taylor and Francis shall not be liable forany losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoeveror howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use ofthe Content.

This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions

http://www.tandfonline.com/loi/tije20

http://www.tandfonline.com/action/showCitFormats?doi=10.1080/09747338.2010.10876065

http://dx.doi.org/10.1080/09747338.2010.10876065

http://www.tandfonline.com/page/terms-and-conditions

http://www.tandfonline.com/page/terms-and-conditions

NanolMicro-Electro-Mechanical Systems forSensor Applications: A Brief Review

V. 5ubrahmanyam, P. 5.5. Narayana Rao

Associate Professor, Ideal Institute of Technology, Kakinada

D.V. Ramamurthy

Principal, Ideal Institute of Technology, Kakinada

P. C. KrishnamacharyCorresponding Author, Principal, Sree Vidyanikethan Engineering CoUege, Sree Sainath Nagar, A.

Rangampet -517 102, Chittoor District, Ap, e-mail: [email protected]

Abstract

Nanotechnology evolved over the past few years and presumably holds the promise of revolutionizing theway we look at things in future. Just as in the case of any other new field, Nano-/Micro-Electro-MechanicalSystems (NEMS/MEMS) involve new materials, new manufacturing procedures, new design/modeling conceptsand new applications of the products developed. It is the objective of this paper to summarize the developmentsin the field of NEMS/MEMS in sensor applications to provide a representative cross-section of the publishedliterature.

Indexing Terms: MEMS, NEMS, microcantilever,young's modulus, piezoresistivity, immobilisation, biosensor

1. INTRODUcnON

D ichard Feynman, in his classic talk in DecemberftI959, titled "There's Plenty of Room at the Bottom- An Invitation to Enter a New Field of Physics" askeda simple question "Why can't we write the entire 24 volumesof Encyclopeadia Britanica on the head of a pin?", to setthe direction of a new branch of fundamental researchin Physics, nanotechnology (also see [1]) andsubsequently to the sub-area NEMS/MEMS. Mter afew decades of leaps and jumps in the field ofnanotechnology, the inaugural issue of NatureNanotechnology asked 13 researchers from different areaswhat nanotechnology means to them and their responses,from enthusiastic to sceptical, reflect a variety ofperspectives [2]. In this scenario, commonly accepteddefinitions of the field of NEMS/MEMS include thedesign, characterization, production and application ofstructures, devices and systems by controlledmanipulation of size and shape at the nanometer (ormicrometer) scale to produce structures, devices, sensorsand systems.

With this background, one might wonder as towhat is the importance of the nanotechnology field.One possible reason is that macroscopic properties ofmaterials may be changed dramatically with nanoingredients. For example, by reducing the grain sizefrom about 100 nm to about 10 nm, the strength of

certain metals may be increased by about ten-fold.Also, certain newer requirements necessitated theuse of extremely small sensing elements thusleading us to the direction of NEMS/MEMS. Forexample, the need to detect a few molecules ofnarcotics or explosives or markers in biotechnologyapplications mandate the use of similarly sizedsensing elements. Yet another requirementmanifested out of the need for dramaticminiaturization which is a call for the day intelecommunication industry, computer industry andgeneral electronics industry.

It may not be possible to summarize thedevelopments in such a diverse field as NEMSIMEMS and layout the evolution of the fieldsystematically in a single paper. However, tointroduce the field to novice readers and tostimulate interest, developments in various alliedsub-fields of NEMS/MEMS are briefly presentedin the following categories.

• Material and manufacturing aspects in Section2,

• Design/Modeling of NEMS/MEMS includingexperimentation techniques in Section 3 and

• Applications including sensors and newermaterials in Section 4.

IETE JOURNAL OF EDUCATION I VOL 51 I ISSUE 1 I JANUARY-APRIL 2010 23

Dow

nloa

ded

by [

Nor

thea

ster

n U

nive

rsity

] at

16:

41 2

0 N

ovem

ber

2014

v. Subrahmanyam et al. : Nano/Micro-Electro-Mechanical Systems for Sensor Applications: A Brief Review

2. MATERIALS AND MANUFACTURINGASPECfS

Several techniques of using micro-cantileverbased sensors were reported and their fabricationtechniques were discussed in [3] and this spurred lotof research on the fabrication of micro-cantilever. Theprocess of fabrication of microcantilever includesdeposition of different layers as wafers on a suitabledie e.g., SU-8 /PolysiliconlSU-8, SU-8/GoldlSU- 8[4, 5]. The different layers deposited are sacrificiallayer, structural layer, piezoresistive layer andimmobilization layer. The first step is the selection ofsacrificial layer deposited over the suitable die overwhich the other layers are formed. Later on thesacrificial layer can be removed by etching processor with a stripper. The structural layer is generallySU-8 or Silicon Nitride. SU-8 is a negative tonechemically amplified near UV photoresistant andchemically inert material [6]. The SU-8 surface canbe modified to make it liable for biomoleculeimmobilization [7]. SU-8 has a low Young's modulus(5GPa) and thus gives better sensitivity. Besides thefabrication is also easy. The layer of SU-8 can beformed by spin coating and doesn't need CVDprocess. [8].

Table 1 : Etchants used for different layer materials

S.No. Layer Material Etchant

1 Photoresist Acetone

2 Silicon Nitride CF +CHF

3 Polysilicon CF+Oo

4 Gold Potassium Iodide (KI)

5 Chromium Ceric Ammonium nitrate (CEN)and Acetic acid in water

The other structural material widely used isSilicon Nitride which is used in biofunctionalizingcantilevers for immobilization of antigens [9].Piezoresistive material (e.g., gold, chromium,polysilicon are commonly used materials)isencapsulated in the structural layer whose electricalresistance changes with deformation. The change inresistance can be measured by using the Wheatstonebridge circuit to estimate the load applied. Polysiliconhas high Young's modulus (130GPa) than Gold (75GPa)and undergoes less deflection as compared to gold.

Immobilisation layer is applied over thestructural layer of biosensing cantilevers which areused to sense the chemical substances, antibodies,explosives etc. The immobilisation layer is a chemical

which reacts with the required analyte e.g., Palladiumcoating absorbs hydrogen and expands [10,11],Myoglobin antibody is used to detect myoglobin [12].

The final step in the fabrication is machining toget the desired shape and size. Before this step, thephotoresist material has to be stripped and any nativeoxide has to be etched by dipping the wafer in asuitable etchant [9, 13]. A few etchants are listed inTable 1.

3. DESIGN/MODELING/EXPERIMENTATION ASPECfS

Some ideas from thin films field may beborrowed and exploited into NEMS/MEMS area.For example, techniques for assessing the adhesionof thin film-substrate systems is discussed in [14]. Thescratch technique discussed here uses micromechanicaltest device with a practical resolution of 50 J1N fornormal and tangential loads, 3nm verticaldisplacement and 100 nm x-y displacement. Aschematic of the test apparatus is shown in Figure 1.Though the mathematical modeling and theexperimentation techniques discussed in this paperare not directly applicable to the nano-range (thefilm thickness was 9.1 ,llIll.), this gives a possibledirection for solving testing/design challenges ofNEMS/MEMS field.

Vibration dampers which shift the naturalfrequency of single/two degree of freedom systemstowards a desirable value are well known inMechanical engineering applications. This idea is usedfor the first time in [15] to facilitate the detection ofa few molecules of the analyte (dsDNA molecules).Two identical cantilevers with adjustable gap inbetween them are proposed to detect the presence ofthe analyte. When the analyte molecules embedthemselves between the two cantilevers, thedisconnected systems now become one compoundsystem with a corresponding shift in the frequencywhich is a measure of the number of moleculespresent. The device reported in this work was suitablefor detecting less than ten molecules and singlemolecule sensitivity is expected with appropriategeometry modifications.

The mechanical properties of the films used inthe miniaturized sensors are extremely important forthe feasibility and performance of the systems. Hence,accurate methods to test and evaluate the mechanicalproperties is a very important aspect. Several methodsare proposed for finding the mechanical propertiese.g., Young's modulus, Poisson's ratio [5, 14-17]. Staticanalyses of 2-2 multi-layered piezoelecttric curvedcomposites is discussed in [18, 19]

24 IETE JOURNAL OF EDUCATION I VOL 51 I ISSUE 1 I JANUARY-APRIL 2010

Dow

nloa

ded

by [

Nor

thea

ster

n U

nive

rsity

] at

16:

41 2

0 N

ovem

ber

2014


Serre et at [14] proposed a method of evaluatingthe Young's modulus of different micro-machinedstructures such as polysilicon and fJ-SiC cantileverbeams. The beam bending measurement techniqueproposed is schematically shown in Figure 2. Thismethod does not need any vacuum chamber and avery high load resolution with nanometric precisionin the measurement of the cantilever deflection canbe achieved. Since the beam under test and probeform a combination of two springs in series, thestiffness of the probe needs to be estimated beforeexperiment. Also, we can see that the stiffness of theprobe needs to be much less than that of the beamunder investigation for best results. This necessitatesa different probe for each measurement of thestructure.

For chemical and biochemical sensing,cantilever-based micro-fabricated sensors areextensively used. These cantilevers are used asprimary sensing element or variable conversion

elements to respond to changes in temperature, mass,or surface stress and produce a tiny deflection as amechanical response. Several design aspects andfabrication issues about the fabrication of these microcantilevers are discussed in [8]. In this work, amicrocantilever-based foil with representativedimensions indicated, as shown in Figure 3, isconsidered. The shape, resembling a tuning-fork-end,is often used to pack a very long piezo-resistive elementinto a very small size. Both mechanical considerationsand electrical considerations are very systematicallyexplored. For example, it was shown empericallythat placing the piezo-resistive layer away from theneutral axis results in lesser deflection. Simulationsoftware Coventorware was used in performing theanalysis reported in this work.

As discussed in [17], the elastic behavior ofmetallic thin films can differ significantly from theirbulk counterparts owing to their specificmicrostructure and owing to size effects. Thus, it is

Indentor .'+a\l Ad!

~-aScratch -------

track I !: B!

Substrate

Figure 1 : Scratch technique [15].

F

Probedeflection

d

Piezo-electricallycontrolled

stage

----ll----------------\7 Probe

displacementz

I 'I II II II II II • Effective I II beam II length I

I

Figure 2 : Beam bending measurement: the load is applied by an AFM probe [19].


Dow

nloa

ded

by [

Nor

thea

ster

n U

nive

rsity

] at

16:

41 2

0 N

ovem

ber

2014

V. Subrahmanyam et al. : Nano/Micro-Electro-Mechanical Systems for Sensor Applications: A Brief Review

(3)

(2)

(5)

where E is the Young's modulus and v is the Poisson'sratio of the material of the beam. Further, for arectangular beam of length L, fixed at one end andfree at the other, an approximate equation for thedeflection at free end, A~ is given as

Llz == 3(1 - v)e (Ll -Ll )Et 2 0'1 0'2 .

Thus, from the measured deflection, one canuse (3) to find the differential stress. Quantity ofadsorbed analyte may be evaluated if it is related tothe differential stress through a known equation.However, clear cut methods to derive the relationbetween the analyte quantity and the differential stressare not extant in the literature.

Almost invariably, the cantilever beams usedare made up of layers with differing Young's modulus.In such cases, an effective :Young's modulus is often usedto perform the analysis using (3) and/or (2). A formulafor effective Young's modulus is given in [8] as

EI ~ wt (Ei [~; +h;(Z; - ZN)2]), (4)

2:::1 EizihiZN= N

2:i=1 Zihi

Literature seems to suggest that the elasticbehavior and thus elastic constants of thin films candiffer significantly from their bulk counterparts (seefor example [16] and references therein). The reasonattributed was that the specific microstructure such astexture, defects, interface mixing and size effects comeinto play. However, explicit theoretical models toaccount for these in a closed-loop form are not aswidely available as the ones using bulk properties;such molecular dynamic phenomenon are studied in[20-24] in the context of nanometric cutting, polishingand atomic scale friction. A few interesting andelegant theoretical models using the theory ofelasticity as applied to microcantilever were reportedin [3]. For example, resonant frequency method forfinding the adsorbed material, given by the equationwhich stems from the

~m= 4~2 ~:2 -f~) (1)

well-known equation f =2~~ . In (1), K is the

cantilever spring constant, 10, h are the resonantfrequencies before and after adsorption and Am is

Figure 3: Meshed Cantilever Structure [10].

important to study the effect of size on elastic constants the change in the mass due to adsorption. Alsoof polycrystalline thin films. One way to control the presented in [3] is frame work for beam bendinggrain size along one direction at nanometric scales is method for evaluating surface stress as illustrated into prepare multilayers. A system of 20 periods of Figure 4. The radius of curvature of the bent beam,alternating layers of 6 nm thick W-Iayer and 18 nm R, is reported [3] to bethick eu-Iayer on Kapton® was studied in [16] toillustrate the framework to study elastic properties ofpolycrystalline thin films. The experiments revealedthat the X-ray strain was maximum at outermost layers,thus corroborating the observation regarding theneutral axis mentioned in [8].


Dow

nloa

ded

by [

Nor

thea

ster

n U

nive

rsity

] at

16:

41 2

0 N

ovem

ber

2014


based sensors in particular. Figure 6, reproduced fromthis paper, illustrates the contemplated uses ofcantilever-based sensors. In addition to identifyingthe possible uses of microcantilever as a primarysensing element, the paper discusses several variableconversion/output schemes such as resonant massmethod, plate bending method, optical leverdeflection method, capacitive pickup method andpiezoresistive/piezoelectric method. It may be saidthat this paper stands as a good starting point forgaining exposure into the uses of microcantileverbased sensors.

Data processing i.e. printing

Automotive and aerospace

Mobile handsets and consumer electronics

4. APPliCATIONS IN SENSORS

where E~ h~ zi are the Young's modulus, thicknessand distance from neutral axis of the z"lh layer.

An interesting application of MEMS in a yawrate sensor is discussed at length in [26].

Considering a simple model of the vibratorygyroscope shown in Figure 7, the operating principleis discussed. The design specifications to beconsidered, structural design aspects, discussion onmicrofabrication process, analytical computation ofthe natural frequency, numerical studies usingANSYS and details of experimental studies aresystematically laid out in this paper. The references

• Industry and process control [29-31] may stand as a good source of informationfor readers working on the simulation of MEMS used

For the sake of continuity and brevity, a few in vibration applications. One of the most commonapplications as inferred from a few publications will applications of MEMS in industry is pressure sensing.be presented here. A novel Micro- Opto-Electro-Mechanical System

design is discussed in [32]. Design and operationOne of the earliest discussions in the decade

details, mathematical model and background theoryabout Micromechanical cantilever-based systems for and description of experimental setup are discussedbiosensing are given in [3]. This paper, with a in detail in this paper.comprehensive list of references (104 references werelisted), dealt with various aspects of cantilever based Biofunctionalization microcantilevers withsensors such as methods of use, method of secondary silicon nitride based piezoresistive element istransduction, biosensing applications and a future presented in [12]. The schematic of the piezoresistivedirection. This may be said to be a must-read for cantilever, both in plan view and cross-sectional viewthose interested in MEMS in general and cantilever is shown in Figure 8. A very detailed description of

r---------------~___,

MEMS-based sensors are a crucial component incommunication systems, medical equipment,automotive electronics, smart portable electronics suchas cell phones, PDAs and hard disk drives, computerperipherals, wireless device and so on and so on thelist is almost endless. Though the MEMS basedsystems initially gained popularity through theirapplication in the air bag sensors, these are becomingpervasive in many areas such as diaphragm basedpressure sensors, sensors in ink cartridges, motionsensors etc. Figure 5 shows the market scenario forMEMS [25] projected till 2013. As per this reference,the MEMS market today is made up of four majorsectors:

•

••

Figure 4, : Surface stresses on bent beam [5].


Dow

nloa

ded

by [

Nor

thea

ster

n U

nive

rsity

] at

16:

41 2

0 N

ovem

ber

2014

V. Subrahmanyam et al. Nano/Micro-Eleetro-Mechanical Systems for Sensor Applications: A Brief Review

9.000

8.000

.000

5.COO

4 coo

3.000

2000

tCOO

o2IJ06 2007 2010 2011 2013

• Wiredcommunicalions

• Aero$pice. defer;;e,S6Curily

• Medical eleclrolllcs

lna'usby and ~eg9conll<ll

• A UlomlJtr.e

• Mool& Md Con$Urr\f1fE lec1ronlcs

Figure 5 : Expected market share of MEMS through 2013 [27].

I~I

Figure 6 : Schematic to show the possible uses of cantilever.(a) AFM force sensor (b) temperature sensor(c) Medium viscoelasticity sensor (d) mass sensor (end load) (e) stress sensor (f) sensor to monitor thepresence of magnetic beads on the surface [3].

Inertial frame

Figure 7 : Operating principle of a vibratory gyroscope [28].


Dow

nloa

ded

by [

Nor

thea

ster

n U

nive

rsity

] at

16:

41 2

0 N

ovem

ber

2014

V. Subrahmanyam et al. Nano/Micro-Electro-Mechanical Systems for Sensor Applications: A Brief Review

SectionPlane

/Conta~

Pads

~

MeasurementCantilever

ReferenceCantilever

Immobilization

Contact Pad Antibodies jayer~nmmrn WlNV\/If\h'VVli"lV"l Piezoresistive

Layer

StructuralLayer

Susbtrate

Figure 8 : Schematic of piezoresistive cantilever used in [12].

the experiments conducted, including the HotwireCVD cluster system built at Indian Institute ofTechnology, Bombay, fabrication of the nitride/polysilicon/nitride piezoresistive cantilever and entirebio-functionalization process are very clearly laid outin this paper.

It may be noted that the whole issue of Sadhana,that is volume 34, part 4 is devoted to MEMS andvery interesting research work may be found in thatissue.

5. SUMMARY

•

•

geometry of the piezoresistive layer at micro-/nano-Ievel are not widely available.

The fundamental models describing how theadsorbed molecules create stress on thecantilever beam and the exact mechanism ofbeam bending are not widely published for thecantilever based sensors.

Uniform methods to select the various layers inthe sensing element are not explicitly definedand often the designer may have to rely onintuition and/or experience.

There is a rich amount of literature available in thefield of MEMS/NEMS covering various aspects suchas material research, production/manufacturingaspects, modeling M EM S systems, designmethodology applicable to MEMS, experimentaltechniques of MEMS and several applications ofMEMS tailored specific uses. In spite of theseadvances, there appear to be lack of fundamentalanalysis/understanding in the following areas:

Not withstanding the setbacks mentioned above,MEMS/NEMS field is an interesting and excitingfield of practical significance and will continue togrow and reap benefits for the humanity.

REFERENCES

[1] RP. Feynman, Miniaturk/Ltion, ch. There's plenty ofroom at the bottom, pp. 282-296. Reinhold, 1961.

•

•

Though many published works indicate that thebulk properties may be drastically different frommicro-/nano-Ievel properties, fundamentalmodels to account for such size effects are notextant.

Closed-form solutions relating the change in theresistance to the applied stress for a given

[2] "http://www.nature.com/nnano/journal/vl/nl/full/nnano.2006.77.html." Website.

[3] W.Lin, H. Jiang, R Zhang, Q Liang, J. Lu, Y. Xiu,K. Moon, O. Hildreth, and C. Wong, "Nano materialsfor microelectronic and photonic packaging," in2nd IEEE International Interdisciplinary Conferenceon Portable Information Devices, pp. 1-5, 2008.


Dow

nloa

ded

by [

Nor

thea

ster

n U

nive

rsity

] at

16:

41 2

0 N

ovem

ber

2014


[4] K Suganuma, D. Wakuda, M. Hatamura, and K-S.Kim, "Ink-jet printing of nano materials andprocesses for electronics applications," in Proceedingsof HDP 2007, 2007.

[5] R. Raiteri, M. Grattarola, H.:J. Butt, and P. Skladal,"Micromechanical cantileverbased biosensors,"Sensors and Actuators, vol. B79, pp. 115-126, 2001.

[6] N. S. Kale, Making Hotwire CVD a Viable TechnologyAlternative for BioMEMS Applications: DeviceOptimization, Fabrication and Characterization. PhDthesis, Indian Institute of Technology, Bombay, 2007.

[7] C.-w. Baek, Y.-K Kim, Y. Ahn, and Y.-H. Kim,"Measurement of the mechanical properties ofelectroplated gold thin films using micromachinedbeam structures," Sensors and Actuators, vol. A117,pp. 17-27, 2005.

[8] J. Shaw, J. Gelorme, N. LaBianca, W. Conley, andS. Holmes, "Negative photoresists for opticallithography," IBM Journal of Res & Dev (OpticalLithography), vol. 41, no. 1-2, 1997.

[9] lIT Bombay, "A novel dry method of surfacemodification of su-8 for immobilisation ofbiomolecules using hotwire induced pyrolyticprocess." Indian Patent Office, 2004. Indian PatentNo. 213504.

[10] N.S. Kale and V. R. Rao, "Design and fabricationissues in affinity cantilevers for biomemsapplications," Journal ofMicroelectromechanical Systems,vol. 15, pp. 1789-1794, December 2006.

[11] N.S. Kale, A Mehta, M. Joshi, S. Mukhetji, R. Lal,R. Pinto, P. Apte, and V.R. Rao, ''Affinity cantileversand EIS based biosensors for cardiac diagnostics."Internal Document, 2009. lIT Bombay.

[12] N. S. Kale, M. Joshi, P. N. Rao, S. Mukhetji, andV. R. Rao, "Bio-functionalization of silicon nitridebased piezo resistive microcantilevers," Sadhana, vol.34, pp. 1-7, August 2009.

[13] D. Baselt, B. Fruhberger, E. Klaassen, S. Cemalovic,C. B. Jr., S. Patel, T. Mlsna, D. McCorkle, and B.Warmack, "Design and performance of amicrocantilever-based hydrogen sensor," Sensors andActuators, vol. B88, pp. 120-131, 2002.

[14] M. Kriese, D. Boismier, N. Moody, and W.Gerberich, "Nanomechanical fracture testing of thinfilms," Engineering Fracture Mechanics, vol. 61, pp.1-20, 1998.

[15] J. Thaysen, Cantilever for bio-chemical sensingintegrated in a microliquid handling system. PhD thesis,Technical University of Denmark, 2001.

[16] M. Lazzarino, E. D.Marchi,M. Bressanutti, L. Vaccari,S. Cabrini, C. Schmid, R. Poetes, and G. Scoles,"Twin cantilevers with a nanogap for singlemolecule experimentation," MicroelectronicEngineering, vol. 83, pp. 1309-1311, 2006.

[17] C. Serre, A. Perez-Rodriguez, J.Morante, P.Gorostiza, and J. Esteve, "Determination ofmicromechanical properties of thin films by beambending measurements with an atomic forcemicroscope," Sensors and Actuators, vol. 74, pp. 134138, 1999.

[18] O. Castelnau, G. Geandier, P.-O. Renault, P.Goudeau, and E. L. Bourhis, "Characterization andmodeling of the elastic properties of nano-structuredw/cu multilayers," Thin Solid Films, vol. 516, pp.320-324, 2007.

[19] A Kalkman, A H. Verbruggen, and G. C. AM.Janssen, "Young'smodulusmeasurements and grainboundary sliding in free-standing thin metal films,"Applied Physics Letters, vol. 78, no. 18, pp. 26732675, 2001.

[20] Z. Shi and T. Zhang, "Static analyses for 2-2 multilayered piezoelectric curved composites,"International Journal of Engineering Science, vol. 45,pp. 509-524, 2007.

[21] H. Xiang and Z. Shi, "Static analysis for multilayered piezoelectric cantilevers," InternationalJournal of Solids and Structures, vol. 45, pp. 113-128,2008.

[22] R. Komanduri, N. Chandrasekaran, and L. Raff,"Molecular dynamics simulation of the nanometriccutting of silicon," PhilosophicalMaga,zine, vol. B81,pp. 1989-2019, 2001.

[23] R. Komanduri and L. Raff, "A review on themolecular dynamics (md) simulation of machining,"in Proceedings of the Institution of Mechanical Engineers(London), vol. 215B, pp. 1639-1672, 2001.

[24] R. Komanduri, N. Chandrasekaran, and L. Raff, "Mdsimulation of atomic scale friction," Physical Review,vol. B61, pp. 14007-14019, 2000.

[25] S. Bhagavatula and R. Komanduri, "On chemomechanical polishing of silicon nitridewithchromium oxide abrasive, " PhilosophicalMagazine, vol. A74, pp. 1003-1017, 1996.

[26] N. Chandrasekharan, A N. Khajavi, L. Raff, and R.Komanduri, "A new method for molecular dynamicssimulation of nanometric cutting," PhilosophicalMagazine, vol. B77, no. 1, pp. 7-26, 1998.


Dow

nloa

ded

by [

Nor

thea

ster

n U

nive

rsity

] at

16:

41 2

0 N

ovem

ber

2014


[27] "http://www.memsindustrygroup.org/images/newsletter/june2009/isuppli figure l.jpg." Website.

[28] K Venkatesh, N. Pati!, A. K Pandey, and R. Pratap,"Design and characterization of in-plane mems yawrate sensor," Sadhana, vol. 34, pp. 633-642, August2009.

[29] G. Fedder, Simulation of microelectromechanicalsystems. PhD thesis, University of California,Berkeley,1994.

AUTHORS

[30] P. Kwok, "Fluid effects in vibrating micromachinedstructures,"Master's thesis,Massachusetts Institute ofTechnology, 1999.

[31] M. Madou, Fundamentals of Microfabrication. CRCPress: Florida, 1997.

[32] P. M. Nieva, J. Kuo, S.-H. W. Chiang, and A. Syed,"A novel MOEMS pressure sensor: Modelling andexperimental evaluation," Sadhana, vol. 34, pp. 615623, August 2009.

V Subramanyam is an Associate Professor (Mechanical Engineering) at Ideal Institute of Technology,Vidyutnagar, Kakinada.

P S S Narayana Rao is an Associate Professor in ECE, Ideal Institute of Technology Vidyutnagar,Kakinada.

Dwivedula Venkata Ramamurthy received his B. E. in Mechanical Engineering in 1987 fromAndhra University College of Engineering Visakhapatnam, India. He received his M Tech in MechanicalEngineering from lIT Delhi in 1992 and Ph. D. in 2005 from Oklahoma State University. Currently he isthe Principal of Ideal Institute of Technology Kakinada.

P C Krishnamachary received his B Tech in Mechanical Engineering in 1988 from N B K R I ST Vidyanagar, S V University, Tirupati. He received his M E (Specialization in Design) from PSG collegeof Technology, Coimbatore in 1994 and Ph D in Mechanical Engineering from SVU college of engineering S V University Tirupati in 2007. Currently he is the Principal of Sree Vidyanikethan Engineeringcollege, Tirupati.

* * *Paper No IETEJE_2_1O; Copyright © 2010 by the IETE.


Dow

nloa

ded

by [

Nor

thea

ster

n U

nive

rsity

] at

16:

41 2

0 N

ovem

ber

2014

Documents

Nano/Micro-Electro-Mechanical Systems for Sensor Applications: A Brief Review