wireless strain sensors

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WIRELESS STRAIN SENSORS BY: JEVAUGHN JULIUS SUPERVISING PROFESSOR: DR. J.C. CHIAO & DR. SMITHA RAO JULY 16, 2013

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wireless strain sensors. By: Jevaughn Julius Supervising Professor: Dr. J.C. Chiao & Dr. smitha rao JULY 16, 2013. objectives. To create a wireless sensor system to monitor and measure strain at any flexing region. - PowerPoint PPT Presentation

Transcript of wireless strain sensors

WIRELESS STRAIN SENSORS

BY: JEVAUGHN JULIUSSUPERVISING PROFESSOR: DR. J.C. CHIAO & DR. SMITHA RAOJULY 16, 2013

OBJECTIVES

• To create a wireless sensor system to monitor and measure strain at any flexing region. • Main focus on measuring the strain caused on the

membranes of human stomachs and the joints on different fingers.• Use LabVIEW and embedded coding to convert the signals

digitally from the sensors and display on a computer wirelessly.

TEST SETUP• Dupont Kapton Polyimide Film

(1)

• Silver Conductive Epoxy (2)

• Digital Multimeter (3)

• Piezoresistive Sensors (4)

• Kerrigan-Lewis Coil Wire (5)(1)

(2)(3) (4)

(5)

PIEZORESISTIVE STRAIN SENSORS

• All sensors are encapsulated in PDMS: Polydimethylsiloxane

METHOD:

• The sensor is not kept at the joint, but instead a piece of Kapton sheet which is attached to the sensor is kept over the joint. • When the finger is bent, the Kapton sheet bends. This

stretches the sensor attached to the sheet and thereby gives a better sensitivity.

PDMS ENCAPSULATION

STRAIN SENSOR GLOVE• The sensitivity achieved by this

method is far more better than the one achieved by keep the sensor at the joint.

• Since the sensor is stretching instead of bending, we are able to calculate the Gauge Factor of the sensor.

GAUGE FACTOR GRAPH

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.0450

0.51

1.52

2.53

3.54

4.55

f(x) = 3955.85850613475 x² − 77.1586424625102 x + 0.254000143502908

dr/R vs dl/L

dl/L

dr/R

GOING WIRELESS

EZ430-RF2500 (WIRELESS SYSTEM)

NEXT STEP

• To continue to work make strain sensors wireless and apply them at different areas to the human body.• Trying to apply Wheatstone Bridge to our wireless system.

QUESTIONS AND ANSWERS

REFERENCES

• Tata, Uday, Hung Cao, Vaibhav Landge, Cuong M. Nguyen, and J.-C. Chiao. "Wireless Strain Sensor Based on Amorphous Carbon for Human-Motion Detection." N.p., 20-23 Jan. 2013. Web. 22 June 2013.• "The Strain Gage." Sensors, Thermocouple, PLC, Operator Interface, Data

Acquisition, Rtd. N.p., n.d. Web. 6 July 2013. <http://www.omega.com/literature/transacti• "EZ430-RF2500 Texas Instruments | 296-23031-ND | DigiKey." DigiKey Electronics -

Electronic Components Distributor. N.p., n.d. Web. 14 July 2013. <http://www.digikey.com/product-detail/en/EZ430-RF2500/296-23031-ND/1785839>.