This Small Business Innovation research Phase I project is to develop flexible, elastic, superhydrophobic surfaces with a technology that physically transforms surfaces by molding microstructures into base polymers, ceramics or metals on a large scale. Uniquely the surfaces may be highly elastic and flexible; and, the process can manufacture surfaces having multiple structures of different sizes and shapes.
Development and implementation of the proposed manufacturing process will provide a method of manufacturing multi-scale and multi-functional surfaces from every day, low cost materials suitable for consumer products. The work could impact transportation safety (tires, airplanes), low-cost green energy (solar panels, wind turbine blades), improved health (medical devices), increased safety (tool grips, first responder tools) and enjoyment (sports products).
Hoowaki has fabricated surfaces with multiple scale, multi-functional engineered surface structures to create extremely water repellent surfaces that resist damage due to handling. The surfaces are extremely water repellent because of microscale structures that cause water to suspend from the tops of structures, and the microscale structures are protected by larger structures on the surface that block intruding objects that would normally damage the microscale structures. Surfaces that repel water and resist damage can mitigate corrosion which consumes 3% of the US GDP annually. Scalable manufacturing processes must create the extremely water repellent structures for the material to be a reasonable cost. Hoowaki fabricates and sells microstructured steel molds whose replicates have the extremely water repellent structures. The microstructured steel molds can be injection mold inserts, and Hoowaki can create arbitrarily curved steel microstructured surfaces. Hoowaki can fabricate steel microstructured molds of arbitrary size by tiling microstructured steel. Currently Hoowaki fabricates 6"x6" steel molds, and Hoowaki is fabricating microstructured steel rollers so that Hoowaki's customers can fabricate extremely water repellent plastic sheets of arbitrary size in roll-to-roll processes. While extremely water repellent surfaces is one application of Hoowaki's microstructures, Hoowaki is pursuing applications in increasing and decreasing friction depending on microstructure type, nucleate boiling increase for heat transfer, and fluid drag reduction.
