The working principle of resistive tactile sensor cells

Abstract

Tactile sensors systems are very important for today's service robotics. Designed as a holohedral cover for a robot, they are suitable for collision detection when working in unstructured environments, for humanmachine interaction or, with a high resolution, as object sensors enabling dexterous hands for reactive gripping. In this paper, we explain construction and working principle of resistive tactile sensor cells. The latter is based on the change of the electrical resistance between a conductive polymer and at least two electrodes. For this effect, we formulate a model to describe the dependence between the sensor's electrical resistance and the applied load. The model enables further improvements of resistive tactile sensor cells.

Study of Pressure-Sensitive Materials for Floor Sensor Networks

“…In case of the studied piezoresistive materials, the sensor linearity was investigated and well documented by the manufacturers reporting a non-linear behaviour in all cases [8][9][10]. Typical sensor characteristics for three different flat-ended cylindrical indenters having a diameter of 40, 55 respectively 70 mm are shown in Fig.…”

“…2. This solution utilizes a conductive polymer material having a rough surface between the electrodes and itself [8]. If a load is applied to the sensor cell, the rough surface of the sensor material is pressed onto the electrode's surface.…”

“…Fig. 2 Working principle of a piezoresistive pressure sensor [8] Both kind of sensor material show a hyperbolic style characteristic [11] between the applied load and the electrical resistance. This nonlinear behaviour is of special interest e.g.…”

Object identification with tactile sensors using bag-of-features

“…Important properties of a sensor are its spatial and temporal resolution, noise, hysteresis, creep, and aging. Different mechatronic principles have been explored in the past, such as pressure-sensitive conductive polymers [20], piezo-resistive sensors [7], piezo-electric vibration sensors [13], and capacitive sensors which can additionally measure the sheer forces [4] or temperature [3].…”

“…The robot's end-effector is a 1-DOF gripper consisting of two fingers which both are equipped with a Weiss Robotics sensor DSA 9205 for gathering tactile images [20]. Each tactile sensor array contains 84 sensor cells arranged in 6 columns and 14 rows with a size of 24 mm by 51 mm.…”