Printed wireless pressure sensor (Conference Presentation)

Abstract

A Printed pressure sensor is demonstrated to measure dynamic pressure of the blood flow in an artificial blood vessel construct. The sensor is an oscillator with printed inductor and compressible porous PDMS capacitor which responds to the changing pressure. The variable capacitance of capacitor modulates the resonance frequency of the LC oscillator. Outside the vessel a readout coil connected to a network analyzer measures the resonance frequency of the LC oscillator, which changes with the applied pressure in the liquid environment. The inductor coils in the sensor circuit and outer readout coil are optimized for higher wireless response by increasing the trace conductivity and geometric designs. Also the porous PDMS capacitor is tuned by pore size and concentration to increase the reliability and sensitivity under changing pressure. The sensor responded to dynamic liquid pressure in the range of 30~170 mmHg within 50 msec, and the current measurement setup followed pulse frequency up to 144 beats per minute. The application of this sensor can be extended to monitoring fluid pressure in other structures, such as in microfluidic chips and environmental monitoring devices.