Fully Ink-Jet Printed Capacitive Pressure Sensor

In this paper a capacitive pressure sensor with two flexible membranes is presented. The sensor consists of two electrodes on membranes, a spacer and an additional dielectric layer between the electrodes. The sensor is fully printed in an ink-jet printing technology using a nanoparticle silver ink. The polyimide foils are used as membranes, a spacer of the sensor and a dielectric isolation layer. With the pressure applied on the electrodes, the polyimide membranes deflect reducing distance between the electrodes and therefore increasing the capacitance of the sensor which serves as a measure of the pressure applied on the sensor. The fabricated sensor is tested and the measured characteristic of the sensor is presented. The pressure is measured up to 1 bar and the obtained sensitivity of the proposed sensor is 16.7 pF/bar.