With the growing demand for unique multifunctional composite materials for a range of advanced applications that require controlled optical, mechanical or electrical properties, there is a need for scalable fabrication processes that would allow for precise nanostructure control. PRINT is a viable approach for this type of fabrication as it provides complete tunability of the filler particle parameters: shape, size (nanometer to micron), orientation and composition. As the molded particles are in an initially non-aggregated state either in the mold or on a substrate, strategies can be employed to transfer the particles to a matrix without aggregating the particles. Using a layering approach, particles are uniformly dispersed in a polymer matrix to generate complex three-dimensional architectures, where particles cannot aggregate. Both polymer-polymer and polymer-ceramic composites have been generated using this technique, with particle inclusions ranging in size from 7 micron to 200 nm.

Fuel cells provide a means to consume alternative, renewable energy sources and produce significantly fewer environmentally malign byproducts. A promising fuel cell technology is the proton exchange membrane fuel cell, at the center of which is the proton exchange membrane, the target of our research project. Conventional proton exchange membranes are composed of high molecular weight linear polymers that undergo an undesirable balancing of performance and durability and are limited to flat, two-dimensional geometries. The nature of flat membranes provides a restraint on the contact with the adjacent catalyst layer, where the electrochemical processes occur, which limits the performance of the fuel cell.

The approach undertaken by the DeSimone group is to synthesize crosslinked membranes directly from liquid precursors. Because the membranes are crosslinked, the balancing act between performance and durability does not exist and patterned higher surface area membranes can be prepared using PRINT technology. These high surface area membranes have greater contact with the catalyst layer and, as a result, have demonstrated significantly better performance than commercially available standards.