Self-Powered Noncontact Electronic Skin for Motion Sensing

The advancement of electronic skin envisions novel multifunctional human machine interfaces. Although motion sensing by detecting contact locations is popular and widely used in state-of-the-art flexible electronics, noncontact localization exerts fascinations with unique interacting experiences. This paper presents a self-powered noncontact electronic skin capable of detecting the motion of a surface electrified object across the plane parallel to that of the electronic skin based on electrostatic induction and triboelectric effects. The displacement of the object is calculated under the system of polar coordinates, with a resolution of 1.5 mm in the lengthwise direction and 0.76 degrees in the angular direction. It can serve as a human machine interface due to its ability to sense noncontact motions. An additional self-powered feature, enabled by its physical principles, solves the problem of power supply. This electronic skin consists of trilayers of polyethyleneterephthalate-indium tin oxide-polydimethylsiloxane (PDMS) films, and microstructured PDMS as the electrified layer, which can be achieved through simplified, low cost, and scalable fabrication. Transparency, flexibility, and less number of electrodes enable such electronic skin to be easily integrated into portable electronic devices, such as laptops, smart phones, healthcare devices, etc.