Soft Microstructure Arrays: A Multifunctional Microsystem for Mass Transport, Energy Transformation, and Surface Manipulation

Soft materials in ordered microstructures, soft microstructure arrays (SMAs), hold the potential to combine polymer science, surface physics and chemistry, and structural mechanics into an integrated microsystem for a wide spectrum of applications, due to their high specific-area contact surfaces with tunable physical and chemical properties, parallel addressability with high resolution, structural response to a wide range of electromagnetic waves, and mechanical flexibility and elasticity. Inspired by the everyday presence in Nature, such as the lotus leaves that repel water, brilliant hues on butterfly wings, and clingy toes of tree frogs, rationally designed SMAs have witnessed an explosive evolution in the past several years. This paper provides a comprehensive review of the latest progress of SMAs, focusing on the incorporated functionality and their use as smart and programmable systems for the purpose of mass transport, energy transformation, and surface manipulation. The exciting advances of SMAs in lithography, microactuators, biomedical patching, mechanical sensing, superwettability, and surface adhesion are featured. Finally, we highlight the remaining challenges and present future outlooks for SMA’s advancement. This review condenses key discoveries from various SMA-related fields into one place and cultivates shared insights and endeavors to stimulate the development of next-generation soft materials and systems.