Skin-Like Strain Sensors Based on Multiwalled Carbon Nanotube/Polydimethylsiloxane Composite Films

Abstract

This study proposes a skin-like flexible strain sensor based on a multiwalled carbon nanotube/polydimethylsiloxane composite film. The composite membrane features spider leg-like microcracks, lotus root-like connecting filaments, and a lotus leaf-like layered surface texture. Benefiting from the synergistic effect of the hybrid bionic nanostructure, the flexible strain sensor retains the advantages of the traditional crack structure strain sensor with high sensitivity, improves the defects of small strain range and poor linearity, and increases the performance of superhydrophobic self-cleaning. The flexible strain sensor exhibits high sensitivity (gauge factor, GF = 33.08), wide range (0–60%), high linearity (R2 ∼ 0.962), ultra-fast response time (62 ms), and superhydrophobic ability (water contact angle ∼157.3°). In addition, the prepared strain sensor successfully recognized sound waves of different frequencies (0–3000 Hz), speech at different volume levels, and finger and arm bending signals, demonstrating the application prospects of the sensor in the fields of human sound signal detection, human motion detection, and electronic skin of bionic robots.