wireless strain sensors
description
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)
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.
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
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.
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>.