MODELING A CAPACITIVE SENSOR WITH A SOFT FOAM POLYMER LAYER FOR SMALL FORCE MEASUREMENT

Abstract

Numerous types of sensors can be used in mechatronic systems. Flexible sensors have great potential for application in human-machine interfaces, human motion monitoring, artificial electronic skin, and wearable electronic devices. In the field of collaborative robots, sensitive force sensors made of flexible materials are frequently used for measuring very small forces. Finite element simulation is a very useful method for the cost-effective development of these sensors. This paper presents finite element simulation of a small force capacitive sensor. A soft foam polymer is used as the dielectric in the capacitor. A force applied to one electrode of the capacitor produces displacement of the polymer which in turn results in a variable capacitance of the capacitor. The total displacements of the soft foam polymer are presented, and the dependence between capacitance and force is introduced.