Robot fingertip tactile sensing module with a 3D-curved shape using molding technique

Abstract

This paper presents the research findings on a new robot fingertip tactile sensing module, and its simple production method. The module has a three-dimensional curved shape and a radius of curvature of about 7mm similar to that of human fingertip. The size of the module is 16.3mm in depth, 16.6mm in width, and 38mm in height. A thin and flexible sensing part consists of strip-type force sensors with 37 taxels based on a contact-resistance principle. Each cell is 2mm in diameter. The force sensors are evaluated through a calibration setup in order to obtain a static force response. The fatigue test is also carried out to check its durability. The 3D-curved fingertip structure is fabricated by the molding technique known as an effective method for mass production. The force sensing part is inserted into the molded fingertip structure. The assembled robot fingertip module is evaluated through a calibration setup in order to obtain the static and dynamic force responses. The fabricated module can detect both contact force and location simultaneously. The threshold sensitivity of one taxel is about 0.2N. The developed sensing module is compact and replaceable, and its fabrication process is easy and economical.