Ultra-thin Skin Electronics for High Quality and Continuous Skin-Sensor-Silicon Interfacing

Skin-inspired electronics emerges as a new paradigm due to the increasing demands for conformable and high-quality skin-sensor-silicon (SSS) interfacing in wearable, electronic skin and health monitoring applications. Advances in ultra-thin, flexible, stretchable and conformable materials have made skin electronics feasible. In this paper, we prototyped an active electrode (with a thickness $\leq 2$ um), which integrates the electrode with a thin-film transistor (TFT) based amplifier, to effectively suppress motion artifacts. The fabricated ultra-thin amplifier can achieve a gain of 32 dB at 20 kHz, demonstrating the feasibility of the proposed active electrode. Using atrial fibrillation (AF) detection for electrocardiogram (ECG) as an application driver, we further develop a simulation framework taking into account all elements including the skin, the sensor, the amplifier and the silicon chip. Systematic and quantitative simulation results indicate that the proposed active-electrode can effectively improve the signal quality under motion noises (achieving $\ge 30$ dB improvement in signal-to-noise ratio (SNR)), which boosts classification accuracy by more than 19% for AF detection.