High-Resolution Carbon-Based Tactile Sensor Array for Dynamic Pulse Imaging

With the development of modern medicine, the importance of continuous and reliable pulse wave monitoring has increased significantly in physiological evaluation and disease diagnosis. Among them, the 3D reconstruction of the pulse wave is indispensable, and needs rely on ultra-high resolution sensor arrays, that is, high spatial resolution, temporal resolution, and force resolution. Herein, a flexible high-density 32 × 32 tactile sensor array based on pressure-sensitive tunneling mechanism is develpoed. Conformal graphene nanowalls (GNWs) pattern arrays are deposited on micro-pyramidal structural Si substrate via mask-assisted plasma enhanced chemical vapor deposition (PECVD) method and are adopted as pressure-sensitive electrode, exhibiting a spatial resolution of 64 dots/cm², high sensitivity (222.36 kPa⁻¹) and short response time (2 ms). More importantly, HfO₂ tunneling layer can effectively suppress noise current, which made it sense weak pressure signals with 1/1000 force resolution and SNR of 36.32 dB. By leveraging its high-resolution array, more holistic pulse signals are acquired and the 3D shape of the pulse wave are successfully replicated. This work shows high-resolution sensors have significant promise for applications in remote intelligent diagnostics.