Microfabrication of conductive PDMS on flexible substrates for biomedical applications

In this paper, we present microfabrication of a novel photopatternable conductive PDMS material with silver powder as conductive filler and benzophenone as photosensitive component, employing standard photolithography approach. An array of miniaturized capacitive pressure sensors is micromachined onto flexible polymeric transparency using this approach. Highest conductivity of ~10⁴ Sldrm^-1 and minimal feature resolution of 60 mum have been successfully achieved. In addition, a thermal compression step can mold the microfabricated device into a desired shape (e.g., contact lens). The unique combination of physical properties from both silver filler and PDMS matrix along with photopatternability makes the conductive PDMS composite an excellent material for biological and clinical sensing applications.