Keywords
Citation
(2002), "Ultra thin tactile sensor", Sensor Review, Vol. 22 No. 1. https://doi.org/10.1108/sr.2002.08722aab.009
Publisher
:Emerald Group Publishing Limited
Copyright © 2002, MCB UP Limited
Ultra thin tactile sensor
Ultra thin tactile sensor
Keywords: Sensors, Japan
The Industrial Products Research Institute run by the Japanese government's Industrial Science and Technology Agency in Tokyo, has reported the development of an ultra-thin tactile sensor that is just about one-third as thick as existing pressure-sensitive conductive rubber sensors. It measures 4cm by 4cm and has a thickness of 350 microns. The structure consists of a paper spacer sandwiched between flat resistors, which are squares of polyester film coated with a deposited layer of indium oxide. Numerous square "windows" perforate the spacer.
When pressure is applied to the windowed portion of the sensor, the flat resistors on either side of the spacer come into contact, causing an electrical current to flow that converts a pressure distribution. By determining the center of this current distribution, it is possible to learn where the force being applied is centered. When an object moves on the sensor, the center of the pressure distribution shifts, this shift being used to determine the direction, distance, and speed of object movement.
The force-detection sensitivity of the sensor increases with greater window size and smaller space thickness. Sensors of differing pressure sensitivity can be obtained by appropriate adjustments of these two factors and also, when three of the sensors with differing pressure sensitivity are stacked together and used in a robot hand, the orientation of an asymmetrical object can be determined. In order to provide robots with the ability to grasp objects gently, tactile sensors must be made as thin and flexible as possible. These are conditions that have been hard to achieve, and the new sensor seems to meet this requirement.
The Institute expects that the sensor will be useful in robot fingers and in a wide range of other applications, including graphic input devices.