Intellectual Merit: New possibilities would open in many fields if there were straightforward ways to manufacture microspheres with complex surface features. The challenge in accomplishing this goal is the lack of methods for manufacturing micro/nano features on three-dimensional micro-objects in a controlled, yet rapid, robust, and parallel process. This proposal takes inspiration from nature, where fracture of thin films is utilized to produce patterns such as features on cantaloupe skin that form as the surface is strained in response to growth of its interior, to develop a novel fracture-based manufacturing technology. Specifically, a combination of strain-induced fracturing of polymer-supported thin films, surface chemistry manipulations, microfluidics, colloidal assembly, and electroless deposition of metals is used to form micro/nano patterned microspheres. Manufacture of the desired features is guided by computational analysis of the mechanics of thin film fracture on microspheres.
Broader Impact: Efficient manufacture of micro/nano-patterned microspheres will impact many fields such as preparation of photonic materials, study of rheology, development of novel electronic devices, and in the study and manipulation of biological cells. The technology will also impact micro/nano-manufacturing education because the visually striking, experimentally straightforward, and theoretically stimulating nature of the process makes it an inherently useful system to provide introductory hands-on laboratory experiences to students of all levels. This project will particularly focus on providing research opportunities for minority female engineering students and undergraduate students. The theories and experiments developed will also be incorporated into graduate courses in biomedical, mechanical, and materials engineering.
