High Performance Microcrack-based MWCNT-rubber Strain Sensor

Here we report on the design, synthesis and characterization of a stretchable strain sensor using a cracked multi-walled carbon nanotube film plotted on an elastomer sheet substrate. This bilayer sensor was developed for measuring strains at levels much higher than the conventional metallic foil-based strain gauges; while achieving higher gauge factor, lower hysteresis and improved linearity comparing to other current advanced flexible strain sensors. Such improved piezoresistive responses originate from reproducible opening and closing of the uniformly distributed, high density microcracks that were generated in the carbon nanotube thin film during controlled pre-stretch training. The constraining of microcrack opening-and-closing and nanotube rotation help to stabilize and mitigate large strains and significant resistance variation, leading to superior mechano-electric performances.