A reusable high aspect ratio parylene-C shadow mask technology for diverse micropatterning applications

In this paper, we present a low cost, flexible and reusable parylene-C shadow mask technology for diverse micropatterning applications. The smallest feature size of 4 μm is demonstrated and the technology is scalable up to full wafer scale. With the addition of SU-8 pillars, we also demonstrate multimask processing with an alignment accuracy of about 4–9 μm. To achieve features with fine resolution, a low temperature and high aspect ratio (>8:1) parylene etch process is also developed. Utilizing this shadow mask, we successfully patterned proteins and cells on various surfaces (glass, PDMS, methacrylate). High pattern flexibility (structures with different shapes and dimensions are successfully patterned) and patterning on curved PDMS surfaces are also demonstrated. This technology has potential applications for patterning proteins, cells and organic transistors on conventional and/or unconventional substrates.