A Flexible Resonant Pressure Sensor With High Sensitivity and Wide Detection Range

Abstract

In this letter, a flexible resonant pressure sensor is presented. The sensor consists of two parts: a pressure-sensitive capacitor and a pair of inductors. The capacitor and the inductors are connected in series and form an LC resonant tank. The innovation of this sensor is that the dielectric of the pressure-sensitive capacitor, made of polydimethylsiloxane, is enhanced by the anisotropic distribution of nano iron particles (nmFe) inside. This method effectively enlarges the sensitivity and extends the pressure detection range of the device. Furthermore, to improve the sensitivity in a low-pressure range, one side of the dielectric is made into the pyramid topology. The fabricated dielectric is applied to a passive wireless pressure sensor and greatly improves the performance of the devices. The testing results show that the sensor exhibits a high sensitivity of −48 kHz/kPa and a wide detection range of 0–600 kPa.