Direct Write Thermal Spraying of MesoscaleElectronics and Sensor Structures

Novel Approaches to Integrating Sensors on Structures

S.Sampath, R.Gambino, J.Longtin and H.HermanCenter for Thermal Spray Research

Department of Materials Science and EngineeringState University of New York

Stony Brook, NY 11733

R.GreenlawIntegrated Coating Solutions

Huntington Beach, CA

Thermal Spray Direct Write Technology

Virtues and Unique Advantages• High through-put manufacturing• High speed direct writing capability• In situ rapid application of metals, ceramics

and polymers– W/o thermal treatment or post processing

• (Once we write we are done !!)– In situ incorporation of multilayers

& functionally graded layers

• Useful functional material properties in as-deposited state

• Cost effective and efficient• Process virtually in any environment• Minimal heat input into the substrate

Al2O3

Ni

Graded

Thermal Spray Direct Write Deposition CapabilitiesRange of Geometries

• Blanket Deposits: Films and Coatings• Patches• Lines• Vias• Thick deposits and 3-D structures

On plastic, metals, textile and ceramic substrates• Conformal structures• On pre-existing components and structures

Ability to overcoat with a variety of materials forharsh environment applications

Extrordinary Materials Versatility• Dielectrics and sensor ceramics

– alumina, zirconia, yttria, BaTiO3, BST• Conductors

– Cu and Ag• Sensor materials

– NiCr, NiAl, Mo, NiCu etc.• Magnetics

– Permalloy) and MnZn ferrites• Polymers

– Range of thermoplastics• Semicondutors

– Si and Ge

5050 ? mmAlumina

Permalloy

Antenna on ConcreteWith Polymer overcoat

Mesoscale Direct Write Capability

Height ~ 60 ? mBase Diameter ~ 350 ? m

Height ~ 60 ? mBase Diameter ~ 350 ? m

Direct-Write Sensors for Harsh Environments• Harsh Environments

– high temperatures ,corrosive– high vibration, wear, strain, thermal/load cycling, etc.=> Intrinsic capability due to nature of thermal sprayed material and its application

E-type thermocoupleBy direct write

- chromel/constantan- up to 900+ °C- high sensitivity

(> 45 mV/°C) - High reproducibility

NiCu NiCrAluminacoating 0 200 400 600 800 1000 1200

0

10

20

30

40

50

K-type thermocouple

Seebeck coefficientS = 41.7 ?V / °C

Vol

tage

(mV

)

Temperature (°C)

K-type thermocoupleBy direct write

- chromel/alumel- up to 1200+ °C- good sensitivity - robust performance

Flame Impingement Test for Exposed and Embedded Direct Write Thermocouples

• MAPP flame on front of the embedded thermocouple, coated with YSZ thermal barrier coating

• Surface TC: 700 oC• Embedded TC: 435 oC

substrate

thermocouple

YSZ TBC

0 40 80 120 160 200 2400

2

4

6

8

10

12

bare coated (6 mils)

S ~ 43 ? V/deg

Thermocouple K-type

Vol

tage

(m

V)

Temperature (oC)

0

100

200

300

400

500

600

700

800

900

1000

0 1 2 3 4 5 6 7 8 9

Time (minutes)

Tem

per

atu

re (

oC

)

11in

9in

7in

0

100

200

300

400

500

600

700

800

900

1000

0 1 2 3 4 5 6 7 8 9

Time (minutes)

Tem

per

atu

re (

oC

)

11in

9in

7in

Response as a function of standoff distance

Embedded Strain Gauge and Other DevicesEmbedded Strain Gauge and Other Devices

MICEstrain gauges

Commercialstrain gauge

Strain, ? (x10-6)

-250 -200 -150 -100 -50 0 50 100 150 200 250

Res

ista

nce

chan

ge, ?

R/R

(x1

0-6)

-500

-400

-300

-200

-100

0

100

200

300

400

500Commercial SG, GF=2.085Laser-cut SG-load, GF=1.328Laser-cut SG-unload, GF=1.322

• Good repeatability• Good linearity• Negligible hysterisis

= Si= Si= Ni= Ni

15 mm

3 mm

13 mm

3 mm

Prim

ary

Secondary

Prim

ary

Secondary

Inductors/Transformers

Thermistors RF ElementsMagnetic Sensors Microheaters

Applications in a wide range of industries

Aerospace Automotive

Dental Implants/ProstheticsPaper, Textile & Printing Industry

Infrastructure

Mesoscale Electronics and Sensors

Thermal Spray MICE allows sensor integration onto variety of structures embedded within structural coatings

Conformal Direct Write Capability(Prototype Tool and System)

Possible Direct-writtenmultisensor configuration

on a turbine blade

Conformal direct Write cell

Direct write antennaOn helmet

FeedstockDelivery

Diagnostics

Integrationand Control

Motion

Powder Feed

Deposition

WaterCooling

PowerSupply

Gas

Stony Brook Prototype Direct Write Tool

Fine FeatureDevelopment

Vision

Powder Feed

Direct Write Sensors Mobile Application Possibilities

*Support equipment, tethered lines, and effects of gravity omitted for simplicity