(758g) Elastic Networks for Shape-Memory Contact Printing

Current methods for microscale pattern transfer fail to combine high feature resolution, ability to pattern large areas, high throughput and cost effectiveness. Over the past few years, several researchers have demonstrated how films of shape-memory polymers can exhibit topographical memory, leading to switchable adhesion or optical properties. We are designing and developing new stimuli-responsive materials to ultimately enable high fidelity pattern transfer by thermal modulation of the elastomeric contact printing process. Glass forming, semicrystalline, and hydrogen bonding shape-memory networks are prepared and characterized in the bulk and have been molded into films with simple surface features such as spheres, posts, and cones. The influence of temperature and temperature history on the contact mechanics of molded shape-memory thermosets is studied using custom-built materials testing / contact printing apparatus. The apparatus is capable of controlling temperature as well as the compressive strain between two soft surfaces while measuring stress and contact area (optically).  Contact mechanics experiments are modeled and interpreted using finite element analysis to offer deeper insight to the nature of contact and detachment. Micro-indentation and atomic force microscopy studies have also yielded new relationships and valuable insight to enabling shape-memory contact printing.