Design and Output Voltage Model of Folding Magnetized Electronic Skin for Intelligent Manipulator

Abstract

An electronic skin tactile sensing unit with high sensitivity was designed using a magnetic film, a thermoplastic elastomer (TPE) elastic substrate, a silicone elastomer, and a tunnel magnetoresistance (TMR) element. The magnetic film adopts folding magnetization, which can make the folded position have higher magnetic field strength. The output voltage model of the electronic skin sensing unit is established, and the static force test platform is built. The experimental results show that the normal force can be measured within the range of 0.05–6 N, and the measurement sensitivity increases with the increase of the applied force, reaching a maximum value of 559.65 mV/N within 5–6 N. The maximum error between experimental and theoretical values is not more than 3.64%. The response time and recovery time of the sensing array are 37 and 38 ms, respectively. The sensing array can be mounted on a curved surface for pressure detection, and the maximum error does not exceed 5.97%. A <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3\times 3$ </tex-math></inline-formula> electronic skin sensor array is designed, and the interaction between each element in the array does not exceed 4.17%. The sensor array is mounted on the fingertip of the intelligent robot to recognize various object shapes, and the comprehensive recognition rate reaches 95.79%. The results have implications for the development of tactile sensing technology and the design of flexible tactile sensors.