Programmed autonomous microfluidics using microvalves and micropumps

A new concept and devices for autonomous switching of valves and pumps in microfabricated flow channels are proposed. An electrowetting-based valve formed with a gold electrode was opened when an electrolyte solution reached a zinc electrode in a controlling flow channel. Following this, a H₂O₂ solution was introduced into a diaphragm micropump with manganese dioxide (MnO₂) powder. Oxygen bubbles produced by catalytic decomposition of H₂O₂ inflated the diaphragm and moved a solution in a flow channel. Logic circuits were constructed using the valves and flow channels. Additional electrodes, circuits, and instruments were not necessary. Timing for triggering the pumping action could be adjusted by changing the location of valves in a network of flow channels. Furthermore, the autonomous processing of solutions was demonstrated for chemical analysis.