Silk Nanofibers-Based Soft and Degradable Capacitive Pressure Sensor Arrays

Abstract

Highly sensitive pressure sensors with features such as biocompatibility, biodegradability, and flexibility are needed in applications such as robotics, prosthesis, medical implants, and wearable electronics. However, due to material limitations or technological bottlenecks, it is often challenging to fabricate pressure sensors with these attributes at the same time. Herein, we present biodegradable silk/PEO/yeast nanofibers-based soft capacitive pressure sensor array (2×2). The electrospun nanofibers used here have about 150% enhanced crystallinity, as confirmed by X-ray diffraction and Fourier transform-infrared spectroscopy. The performance metrics of the sensor array such as sensitivity (∼0.18 kPa <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> ), hysteresis (<16%), minimum response (∼0.8 s), and recovery time (∼1 s) show its suitability for application such as smart plasters used for accelerated wound healing. Further, the degradability studies confirm the quick degradation of sensors, which can also be potentially controlled with suitable packaging.