Flexible Piezoelectric Tactile Sensor Array for Dynamic Three-Axis Force Measurement
Open Access
- 3 June 2016
- Vol. 16 (6), 819
- https://doi.org/10.3390/s16060819
Abstract
A new flexible piezoelectric tactile sensor array based on polyvinylidene fluoride (PVDF) film is proposed for measuring three-axis dynamic contact force distribution. The array consists of six tactile units arranged as a 3 × 2 matrix with spacing 8 mm between neighbor units. In each unit, a PVDF film is sandwiched between four square-shaped upper electrodes and one square-shaped lower electrode, forming four piezoelectric capacitors. A truncated pyramid bump is located above the four piezoelectric capacitors to improve force transmission. A three-axis contact force transmitted from the top of the bump will lead to the four piezoelectric capacitors underneath undergoing different charge changes, from which the normal and shear components of the force can be calculated. A series of dynamic tests have been carried out by exerting sinusoidal forces with amplitudes ranging from 0 to 0.5 N in the x-axis, 0 to 0.5 N in the y-axis, and 0 to 1.5 N in the z-axis, separately. The tactile units show good sensitivities with 14.93, 14.92, and 6.62 pC/N in the x-, y-, and z-axes, respectively. They can work with good linearity, relatively low coupling effect, high repeatability, and acceptable frequency response in the range of 5–400 Hz to both normal and shear load. In addition, dynamic three-axis force measurement has been conducted for all of the tactile units. The average errors between the applied and calculated forces are 10.68% ± 6.84%. Furthermore, the sensor array can be easily integrated onto a curved surface, such as robotic and prosthetic hands, due to its excellent flexibility.Keywords
This publication has 22 references indexed in Scilit:
- Detection and prevention of slip using sensors with different properties embedded in elastic artificial skin on the basis of previous experienceRobotics and Autonomous Systems, 2014
- POSFET touch sensor with CMOS integrated signal conditioning electronicsSensors and Actuators A: Physical, 2012
- Detection system of incident slippage and friction coefficient based on a flexible tactile sensor with structural electrodesSensors and Actuators A: Physical, 2012
- Tactile sensing for dexterous in-hand manipulation in robotics—A reviewSensors and Actuators A: Physical, 2011
- Piezoelectric oxide semiconductor field effect transistor touch sensing devicesApplied Physics Letters, 2009
- Artificial Roughness Encoding with a Bio-inspired MEMS-based Tactile Sensor ArraySensors, 2009
- Coding and use of tactile signals from the fingertips in object manipulation tasksNature Reviews Neuroscience, 2009
- Tri-Axial Sensors and Actuators Made of a Single Piezoelectric Cylindrical ShellIEEE Sensors Journal, 2004
- Object imaging with a piezoelectric robotic tactile sensorJournal of Microelectromechanical Systems, 1995