Highly Transparent Porous Polydimethylsiloxane with Micro-Size Pores Using Water and Isopropanol Mixture

This paper reports a fabrication method of highly transparent closed-cell type porous polydimethylsiloxane (PDMS). The effect of various chemicals together with water was investigated for the inner pore formation when fabricating porous PDMS. Among them, the mixture of water and isopropanol (IPA) into PDMS was effective for reducing the average size of pores. The size and distribution of pores in PDMS were evaluated with an image process technique. In addition, the reducing mechanism of pore size was proposed and experimentally verified through adjusting the ratio of water and IPA in the mixture. This reduced size of inner pores in PDMS results in high transparency.