Preparation and characterization of highly elongated polydimethylsiloxane nanosheets

Abstract Polydimethylsiloxane (PDMS) is a biocompatible polymer that exhibits high flexibility and heat resistance. PDMS can be rapidly cross‐linked at low temperatures by a platinum‐catalyzed addition reaction and is used to create nanostructures owing to its high formability. In this study, free‐standing PDMS thin films (PDMS nanosheets) were fabricated and characterized. PDMS nanosheets, about 90–2500 nm thick, were prepared using a microgravure coater. The mechanical properties of the PDMS nanosheets depended on the amount of cross‐linker added in preparation. For example, a 93‐nm‐thick PDMS nanosheet showed high flexibility with elongation at break of 338% and Young's modulus of 0.46 MPa. The adhesion strength of the PDMS nanosheets was also dependent on the amount of cross‐linker, and the lesser the cross‐linker, the higher the adhesion strength. The PDMS nanosheets showed no change in physical properties when annealed at 150°C. Flexible, adhesive, and heat‐resistant PDMS nanosheets were demonstrated as a substrate for skin‐contact strain sensors and showed resistance changes of 20%–30% in response to skin stretching.