Flexible Inductive Pressure Sensor Array

Abstract

Elastic magnetorheological materials are gaining popularity due to their flexibility and adaptability. Pressure sensors have important applications in robotics, E-skin and industry. In this paper, an innovative flexible magnetic material inductive pressure sensor array is presented based on cast Ecoflex material with magnetic filler. A 4×4 sensor array is demonstrated using an inductive readout technique. The individual pixels of the array were calibrated and show a highly linear response with a R2 of 0.9953 and a sensitivity of 4.789 pHPa-1. The mutual interference between pixels in the array was measured. Based on this, the spatial resolution is improved using the mutual inductance between neighbouring sensors with a maximum-likeliness estimator. This allows the spacial detection of pressure and gestures with sub-pixel accuracy. The developed array is also bend tolerant, it was tested under repeated strain and bent around a 7mm diameter rod without significant variations of the sensor performance.