Optical type strain sensor based on variable-transmittance of carbon nanotube embedded elastomer thin film

In this work, we report a novel optical type flexible and stretchable strain sensor based on a carbon nanotube(CNT)-elastomer nanocomposite thin film. At the initial state, the percolated CNTs embedded on the surface of the elastomer film block most of the light illuminated on the film. As an external tensile strain is applied to the CNT-elastomer film, cracks on the film are generated and propagated, leading to an increase of optical transmittance of the CNT-elastomer film, which can be detected by a photodetector. The sensor shows a great strain sensing performances with high sensitivity, quick dynamic response, small hysteresis, high stability, and independence on light intensities.