Strain-Dependent Resistance of PDMS and Carbon Nanotubes Composite Microstructures

We report the development of a micropatterned nanocomposite composed of elastomer poly(dimethylsiloxane) (PDMS) and multiwalled carbon nanotubes, and its resistive response to large mechanical deformations. Microstructures of nanocomposite were embedded into unfilled PDMS to work as a strain sensor and devices were fabricated with simplicity through microcontact printing and screen-printing approaches. When subject to large tensile strains (>45%), nanocomposite sensors revealed significant change in electrical resistance. Also, cyclic loadings of sample yielded repeatable resistive responses. An interesting observation of hysteresis effect was confirmed with multiple tests and possible underlying mechanisms were discussed. As a flexible and biocompatible elastomer, the micropatterned nanocomposite could prove useful in sensing biomechanical strains and other various applications.