An Epidermal Stimulation and Sensing Platform for Sensorimotor Prosthetic Control, Management of Lower Back Exertion, and Electrical Muscle Activation

An epidermal stimulation and sensing platform is demonstrated where multiple transcutaneous electrical stimulation electrodes cointegrate on a common substrate with sensors for electromyography, temperature, and mechanical strain. The layout includes electrodes for electrotactile stimulation and measurement of EMG signals, temperature, and strain. The temperature sensor consists of a serpentine conductive trace (Cr/Au) with a width of 20 μm, thickness of 200 nm, and total length of 26 mm in which the temperature coefficient of resistance in the Au serpentine traces provides the basis for the measurement. The EMG sensor uses the same metal, patterned in a different geometry, for reference, measurement and ground electrodes that each consist of 20 μm wide circular concentric rings in an interwoven serpentine morphology to allow mechanical stretchability, and with a spacing of ?10 mm to optimize signal quality. The EMG and stimulation electrodes remain exposed to the skin. All sensors connect to peripheral contact pads that allow interfaces to external power supplies and data acquisition hardware. The stimulation electrodes provide an important functional capability.