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A Bio-Inspired Nanocomposite for Photocurrent-Based Strain Sensing

D. RYU, K. J. LOH

Abstract


In this study, a photosynthesis-inspired nanocomposite strain sensor is proposed, and its sensing performance is characterized. Contrary to conventional strain sensors, the proposed sensor can measure applied strains using photocurrent generated by ambient light illumination and thus do not require an external power source for longterm operations. First, fabrication of the poly(3-hexylthiophene) (P3HT)-based multilayer thin film using spin coating is presented. Holes and electrons can separate at p-n heterojunctions within the P3HT-based photoactive layer to generate photocurrent. In addition, films with and without double-walled carbon nanotubes (DWNT) will be investigated. Second, photocurrent generation validation tests of the two types of films will be conducted. It has been found that the films generate time-variant photocurrents but can be fitted using an exponential decay model. Finally, both types of films will be subjected to tensile cyclic loading while their generated photocurrent is recorded. The results show that films enhanced by DWNTs will increase their photocurrent generation in tandem with increasingly applied strains and exhibit good linearity, repeatability, and high strain sensitivity of 6.03.

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