Fabrication of Polymeric Nano-Valve Array for Biomedical Applications

Electro-active polymer working in aqueous medium has short response time and small power consumption. Polypyrrole is one of such electro-active polymers. Due to its stability, incorruptibility and micromachining compatibility, polypyrrole plays an important role in developing micro/nano-actuators for biological and chemical applications. This paper presents a flexible and reusable polypyrrole nano-valve array for biomedical applications. The nano-valves are formed by depositing polypyrrole on the anodic aluminum oxide (AAO) film by a novel method to ensure the integrity of the AAO film. The valves are actuated through the oxidation and reduction of the polypyrrole. The oxidation state of the polypyrrole makes sodium ions leaving the polypyrrole and hence contracts the polypyrrole. So the gold/polypyrrole bilayer was bended and the valves blocked. Conversely, the valve is opened as the reduction state. By controlling the open/close time with constant voltage, the diffusive quantity of the nano-valves can be easily changed.