Flexible polyimide based capacitive displacement sensor

Abstract

© 2017 IEEE. The aim of this work is to investigate the polyimide based capacitive sensor for displacement measurements. The working principle of the proposed sensor is based on the change in the capacitance under displacement of an upper electrode fabricated on a polyimide membrane while the lower electrode is fixed. The nanoparticle silver ink is used for ink-jet printing of the electrodes on the polyimide foils. The spacer with the air gap cavity between the electrodes is obtained by a cold lamination process of the polyimide layers. By displacement of the upper electrode, the electrodes are closer each other so the capacitance of the sensor is greater. The changes of the sensor's capacitance are used as a measure of displacements up to 700 μm with the resolution of 50 μm.