High-Resolution Self-Assembly of Functional Materials and Microscale Devices via Selective Plasma Induced Surface Energy Programming.

Current technologies preclude effective and efficient self-assembly of heterogeneous arrangements of functional materials between 10-1 and 10-5 m. Consequently, their fabrication is dominated by methods of direct material manipulation, which struggle to meet the designers' demands regarding resolution, material freedom, production time, and cost. A two-step, computer-controlled is presented, multi-material self-assembly technique that allows heterogenous patterns of several centimeters with features down to 12.5 µm in size. First, a micro plasma jet selectively programs the surface energy of a polydimethylsiloxane substrate through localized chemical functionalization. Second, polar fluids containing functional materials are simplistically introduced which then self-assemble according to the patterned regions of high surface energy over timescales of the order of seconds. In-process control enables both high-resolution patterning and high throughput. This approach is demonstrated to produce heterogenous patterns of materials with varying conductive, magnetic, and mechanical properties. These include magneto-mechanical films and flexible electronic devices with unprecedented processing times and economy for high-resolution patterns. This self-assembly approach can disrupt the current lithography/direct write paradigm that dominates micro/meso-fabrication, enabling the next generation of devices across a broad range of fields via a flexible, industrially scalable, and environmentally friendly manufacturing route.