IDC based battery-free wireless pressure sensor

In this paper a battery-free wireless pressure sensor is presented with design of two major parts: a interdigital capacitor (IDC) that serves as a pressure sensing element and an inductor which works as a passive power source and data communication element. These two components work together as an LC resonator to realize the wireless pressure sensing and remote power to eliminate the need for wire connection in conventional pressure sensor. The sensing element is comprised of a set of linear parallel electrodes coated with Polyvinylidene Fluoride (PVDF) pressure sensing material on the top. The change of capacitance in the IDC is a function of the geometry of the electrodes and the electric properties of the sensitive layer. . The sensor prototype has been made and experiment demostrated that the sensor protoype performs well in arange of 0 psi to 60 psi with an average pressure sensitivity of 25KHz/psi.