Elastic Force Sensor Based on Velostat® Characteristics Investigation

Velostat® is carbon black based elastic foil which changes its resistance based on applied force, so it may be used as a force sensor. It enables to produce elastic toys and wearable electronics products for human health monitoring. As well as it enables us to design matrix sensors which offers pressure distribution monitoring even on irregular shapes. The biggest advantage of Velostat® is its flesibility which gives wide variety of applications. On the other hand, the material has strongly nonlinear behavior with hysteresis loop. The purpose of the presented research is designing, implementation and measurement of electro-mechanical characteristics of pressure sensor made. The Velostat® was used as a sensing material for self-made pressure sensor in matrix structure. In this scope only one sensory cell is taken under measurement during one measurement procedure. Automated measurement stand is presented as well as measurement procedures and results with analysis. Research confirmed high nonlinearity and hysteresis loop. In addiction the hysteresis significantly depends on velocity of force stimulus. Exemplary, for velocity of force decreasing equal to 100 mm/min resistance returns to its nominal value after force achieves 0 N.