Dynamic hand gesture recognition using a stretchable multi-layer capacitive array, proximity sensing, and a SVM classifier

Hand Gesture Recognition (HGR) has application in Human Machine Interfaces (HMIs), to control robots, games, and machines. Here we demonstrate a soft-matter multi-layer printed electronic circuit, that can be used to detect the human gesture without the need for physical contact, except for unlocking the system. The film is able to detect touch and proximity of the hand at various nodes, and thus is able to construct an image of the hand. This is performed through fabrication of a thin, stretchable, high resolution, and multilayer circuit, that embeds a mesh of capacitive sensors for human gesture detection, through proximity sensing. The film is fabricated by superposing 6 layers: 3 insulating polymer layers, two EGaIn liquid metal layers patterned in shape of a mesh, and one flexible printed circuit board (FPCB) layer. The fabrication technique absed on spray deposition of EGaIn liquid metal is fast, low-cost, and easy, and can be used for scalable fabrication of large area multi-node sensing surfaces, with application in Robotic e-skins, and general Human Machine Interfaces. The system is trained with five gestures, including dynamic gestures. We demonstrate classification of these gestures using a support vector machine (SVM) based algorithm.