Design of a Wireless Passive Pressure Measurement System Using Piezoresistive Materials.

In this article, a methodology for wireless and passive pressure measurement systems has been presented based on the principle of inductive-capacitive (LC) sensing. In the proposed method, two flexible carbon composite materials: Velostat and carbon conductive foam have been chosen as the pressure sensing element. Both the materials have the property of piezoresistivity and show the change in resistivity with applied pressure. In the designed sensor, the LC circuit has been modified into an LCR tank circuit with a variable resistor as a sensing element. During the measurement, pressure has been monitored and measured using a reader coil, connected with the impedance analyzer. The change in resistance in Velostat or conductive foam with applied pressure, changes the input impedance, quality factor, and resonance frequency. The proposed measurement system has shown an innovative technique based on an LC pressure measurement system with a resistive sensing element. Both the sensing materials have been taken separately and individual experiments have been performed. The method has been tested and evaluated experimentally, which also analyzes the two carbon-composite-based materials for this type of wireless pressure sensor. [ABSTRACT FROM AUTHOR]