Multi-functional soft materials based on structural and interfacial engineering of ordered three-dimensional composites

Abstract

The intensive development of nanotechnologies offers a new route to construct sophisticated architectures of emerging soft applications. Among the many classes of stretchable materials, three-dimensional (3D) nanostructured poly(dimethylsiloxane)(PDMS) has emerged as a vital building block based on its merits of flexibility, stretchability, porosity, simple processing, and, more importantly, high degrees of freedom of incorporation with other functional materials, including metals, ceramics, semiconductors. The artificially designed geometries play important roles in achieving the desired mechanical, electrical, and optical performances of devices and thus show great potential for applications in the fields of stretchable displays, sensors and actuators as well as in health-monitoring device platforms. Meanwhile, novel lithographic methods to produce stretchable platforms with superb reliability have recently attracted research interest. The aim of this thesis is to focus on the fabrication of the 3D nanostructured PDMS with high periodicity in nanoscale and their promising soft applications such as piezo-resistive strain sensor and mechano-responsive optical film. For another promising application that requires the enhanced optical/chemical properties using the geometric advances of the 3D nanostructure, the high-performance chemo-resistors based on the 3D nanostructured semiconducting oxide that can effectively utilize gas dynamics and light absorption is demonstrated. Finally, this thesis is concluded with a brief outlook and further research directions.