The research objective of this grant is to elucidate the fundamental mechanism of novel polymer systems capable of dynamically transforming their surface patterns and roughness under the control of electrical voltages. These so-called transformative skins are based on a new mode of surface electromechanical instability recently discovered by the PIs. The instability leads to a rich variety of surface patterns ranging from randomly oriented creases and craters to aligned lines with tunable feature sizes from millimeters to tens of nanometers. The proposed project will integrate a suite of experimental, theoretical, and computational tools to systematically understand the surface electromechanical instability. Specific goals include the development of 1) an experimental system to simultaneously generate instability patterns and characterize their three-dimensional topography under voltages, 2) a non-linear field theory to analyze the formation of the instability patterns, and 3) coupled-field models and numerical methods to simulate the formation and evolution of the instability patterns.
If successful, this interdisciplinary collaborative effort will lead to the first systematic understanding of surface electromechanical instabilities, with the potential to significantly expand the use of functional surfaces and electrical polymers. The novel transformative skins have a broad range of important applications, including on-demand super-hydrophobicity, adaptive optics, controlled adhesion, transfer printing, and antifouling. Conversely, surface electromechanical instabilities can trigger electrical breakdowns and failures of various polymers in energy applications, including insulating cables, organic capacitors, polymer actuators, and generators. The current project will provide a theoretical foundation for judicious design of electrical-polymer systems by either harnessing or eliminating the same instability for different applications. Graduate and undergraduate students will receive training in both numerical and experimental methods related to soft and active materials. This grant further includes a coordinated effort to recruit students from underrepresented populations in science and engineering to enter into this exciting new field of research.
