Development of Transparent, Flexible, Superoleophobic Materials

Amy Tsui1, Wonjae Choi2, Anish Tuteja3, Robert E. Cohen4, and Gareth H. McKinley2. (1) Chemical Engineering, Rutgers University, New Brunswick, NJ 08901, (2) Mechanical Engineering, Massachusetts Institute of Technology, Building 3-252, 77 Massachusetts Avenue, Cambridge, MA 02139, (3) Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Bldg. NE-47, Room 583, Cambridge, MA 02139, (4) Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., 66-554, Cambridge, MA 02139

While superhydrophobic materials like the lotus leaf exist in nature, superoleophobic materials do not. Researchers have already been able to create superoleophobic surfaces using micro-hoodoo structures on a surface to enhance its non-wetting properties, but these are often not mechanically robust or have limited use due to its rigidity. Creating superoleophobic materials that are both transparent and flexible is an important innovation that is expected to expand the usefulness of these surfaces across many areas. This work experimented with various micro-hoodoo fabrication methods including compression, dipping, and stamping under a range of conditions using polydimethylsiloxane (PDMS) and Tecnoflon polymers. These polymers are shown to be effective materials to make micro-hoodoo surfaces that can be transparent and flexible but an efficient and reliable process for making transparent, flexible, superoleophobic materials is still a challenge. While compression is most promising, results are non-reproducible with various defects. An important milestone is that polymeric micro-pillars, the base for micro-hoodoo fabrication, can be reliably produced from molds created by photolithography methods. Once an effective method for fabricating polymeric micro-hoodoos is determined, these superoleophobic materials can allow many products and devices to be resistant to fouling, saving significant money, time and effort in many industries.