Piezoelectric Tactile Sensor Research Articles

A piezoelectric tactile sensor with three sensing elements for robotic, endoscopic and prosthetic applications

This paper reports on a prototype tactile sensing system with only three sensing elements. The magnitude and position of the applied force is obtained by utilising triangulation approach combined with membrane stress. Some information about the shape of the contacted object is obtained. The polyvinylidene fluoride (PVDF) sensor is designed to overcome the problems of cross talk between sensing elements and to reduce the complexity associated with some PVDF tactile sensors arranged in matrix form. A theoretical analysis of the sensor is made and compared with experimental results. The limitation of the sensor is also reported. The sensor in miniaturised form can also be integrated into an endoscopic grasper and a prosthetic finger.

Piezoelectric tactile integrated circuit sensor

A two‐dimensional, electrically multiplexed tactile sensor was realized by coupling a piezoelectric polyvinylidene fluoride (PVDF) polymer film to a monolithic silicon integrated circuit (IC). The IC incorporates 64 sensor electrodes arranged in a symmetrical 8×8 matrix. Each electrode occupies a 400×400‐μm square area, and they are separated from each other by 300 μm. A 40‐μm‐thick piezoelectric PVDF polymer film was attached to the electrode array with a nonconductive urethane adhesive. The response of the tactile sensor is linear for loads spanning 0.8–135 grams of force (gf). The time required to electrically interrogate, measure, and record the response of the sensor’s set of 64 taxels is less than 50 ms, the hysteresis level is tolerable, and, for operation in the sensor’s linear range, taxel crosstalk is negligible. The historically persistent stability and response reproducibility limitations associated with piezoelectric‐based tactile sensors have been resolved by implementing a precharge voltage...

Development of a Tactile Sensing Probe utilizing Piezoelectric Material for Coordinate Measuring Machines.

In this paper, a piezoelectric tactile sensor designed to detect the contact point is proposed for a probe in coordinate measuring machines. The proposed sensor, which is composed of piezoelectric polymer film, resistance layer, and electrodes, is able to detect the contact point from an electric charge at electrodes, which is generated at the contact point. The sensor is sufficiently thin (100-150μm) and soft that it can be applied to a curved surface. A column-shaped probe utilizing the sensor for the detection of the θ-coordinate of the contact point is developed. A neural network is proposed as a method for the detection of the θ-coordinate from electric charge ratios at electrodes. Results of θ-coordinate detection obtained by experiment are not yet accurate enough to contribute to the improvement of measuring accuracy, however, they can be improved by uing electric signal with better S/N ratio.