Flexible, Piezoresitive Touch Sensing Array

摘要

Touch sensing arrays can provide information about both the magnitude and location of contact between a robotic gripper and an object in prehension. By providing a limited imaging capability, tactile arrays aid in evaluation of the state and progression of manipulative tasks. Most tactile arrays however have been built on rigid planar substrates and have therefore been limited to the provision of planar touch surfaces. For grippers of greater kinematic complexity than simple parallel jawed mechanisms, planar touch surfaces can limit the range of manipulative tasks that can be performed. A flexible touch sensor has been designed and constructed to allow tactile sensing over nonpianar surfaces. The sensor uses a force sensitive resistive polymer as the transductive medium. The polymer is deposited in row and column patterns on a thin flexible substrate, providing a low profile, nonrigid sensing device. The sensor operates as a resistance grid with an effective variable resistances between each row and column of the device. Each sensitive site is independently addressable and provides a resistance value that decreases exponentially with applied normal force. A set of 16 x 16 arrays has been built and tested and are currently in use as tactile sensors on Utah/MIT Dextrous Hand.