Design of Flexible Tactile Electronic Skin Array Based on Magnetic Thin Films and Its Position-Sensing Applications

Abstract

To enable robots to perform precise operations, it is essential to equip them with extensive electronic skin to enhance their perceptual capabilities for sensing external information. Mimicking the structure of human skin, we have designed a flexible tactile electronic skin array capable of timely responses to external tactile stimuli. The electronic skin features a sandwich structure, comprising magnetic thin film, a silicone buffer layer, and tunnel magnetoresistive elements. Experiments on point pressure, point distance, and point angle are used to understand the basic characteristics of the magnetic sensing element, and the size of the position-sensing unit is determined with COMSOL simulation. The size of the array can be expanded as necessary, based on specific requirements and practical considerations. Based on the flexible tactile electronic skin array, we propose a novel position recognition method that utilizes the co-coupling of multiple magnetic sensing elements to determine the position information of contact forces. We designed a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10\times 10$ </tex-math></inline-formula> grid experiment using convolutional neural networks (CNNs) to classify each grid position, and the results show a recognition accuracy of 91.2% and a resolution of 1 mm.