Bioinspired Low Hysteresis Flexible Pressure Sensor Using Nanocomposites of Multiwalled Carbon Nanotubes, Silicone Rubber, and Carbon Nanofiber for Human–Computer Interaction

Abstract

The development and utilization of flexible piezoresistive sensors based on bionic nanomaterials have garnered considerable attention due to their broad potential in various domains. However, the key to their enhanced performance lies in incorporating microstructures and conductive coatings, which maximize initial resistance and minimize resistance upon pressure application, thereby amplifying the change in resistance signal. In this study, we draw inspiration from the microconvex structure observed on the skin of crocodiles and propose a bionic-structured flexible pressure sensor. The sensor is fabricated using nanocomposites comprising multiwalled carbon nanotubes, silicone rubber, and carbon nanofiber in conjunction with a three-dimensional (3D)-printed bionic structural mold. Sensor structure is similar to a sandwich structure with three layers: a flexible substrate layer, a sensing layer, and an interdigital electrode layer. Our sensor exhibits improved pressure-sensing capabilities, characterized by rapid response and recovery times (25 ms), a wide pressure detection range (0−80 kPa), minimal hysteresis (2.44%), high sensitivity (0.4311 kPa −1 within the 0−10 kPa range), and fine stability (withstanding 6000 cycles under varying pressures). Notably, this sensor has an efficient sensing ability, long-term stability, and good waterproofing properties, expanding its potential applications in human−computer interaction, motion monitoring, intelligent robotics, and underwater rescue operations.