Abstract:
The responsive micro/nanoscale patterns on the surface whose morphology can be tuned dynamically by environmental stimulus can possibly enable the on-demand control of the surface properties, and provide an important alternative to realize the smart surface. Therefore, responsive patterns have attracted much attention because of a wide range of potential applications in optical devices, responsive microfluidic channels, flexible electronic devices, switchable wettability, and smart display. However, it is still challenging to fabricate responsive patterns with dynamically controlled topographies to realize a smart surface. Recently, Jiang's group first reported a simple yet versatile strategy for the fabrication of near-infrared light (NIR)-responsive dynamic wrinkles by using carbon nanotube (CNT)-containing poly(dimethylsiloxane) (PDMS) elastomer as the substrate for a bilayer system, with different types of functional polymers serving as the top stiff layers. The high photon-to-thermal energy conversion of CNT leads to NIR-controlled thermal expansion of the elastic CNT-PDMS substrate, resulting in dynamic regulation of the applied strain of the bilayer system by the NIR on/off cycle to obtain a reversible wrinkle pattern. The switchable surface topological structures may switch between the wrinkled state and the wrinkle-free state within tens of seconds upon NIR irradiation. The NIR-driven dynamic wrinkle pattern holds promise in potential applications of smart displays, dynamic gratings and light-control electronics, etc.