Ultrasensitive Cracking-Assisted Strain Sensors Based\non Silver Nanowires/Graphene Hybrid Particles

Abstract

Strain\nsensors with ultrahigh sensitivity under microstrain have numerous\npotential applications in heartbeat monitoring, pulsebeat detection,\nsound signal acquisition, and recognition. In this work, a two-part\nstrain sensor (i.e., polyurethane part and brittle conductive hybrid\nparticles layer on top) based on silver nanowires/graphene hybrid\nparticles is developed via a simple coprecipitation, reduction, vacuum\nfiltration, and casting process. Because of the nonuniform interface,\nweak interfacial bonding, and the hybrid particles’ point-to-point\nconductive networks, the crack and overlap morphologies are successfully\nformed on the strain sensor after a prestretching; the crack-based\nstain sensor exhibits gauge factors as high as 20 (Δε\n< 0.3%), 1000 (0.3% < Δε < 0.5%), and 4000 (0.8%\n< Δε < 1%). In addition, we demonstrate the sensing\nmechanism under strain results in the high gauge factor of the strain\nsensor. Combined with its good response to bending, high strain resolution,\nand high working stability, the developed strain sensor is promising\nin the applications of electronic skins, motion sensors, and health\nmonitoring sensors.