Improved Tactile Sensors

Abstract

Next generation robot grippers should be equipped with tactile sensors providing a sense of touch similar to the human hand by measuring the local distribution of forces on the surface.In this Paper two realized sensor types are presented. The first type of tactile sensors are capacitive sensors. Suitable materials for the electrodes and for the dielectric are carefully selected. To increase the sensitivity a multilayer technology and the embedding of conductive particles in the dielectric are performed.The second type of sensors uses a piezoelectric film of the polymer polyvinylidenefuoride (PVDF) as a sensor material. A tactile sensor with a spherical surface is constructed to measure the force distribution during rolling a workpiece on the finger tips. Using a special circuitry, quasistatic measurement can be achieved. Two steps to reduce the influence of temperature are realized. The measured characteristics of the realized sensor are presented.