Programmed autonomous valve operation based on electrowetting on composite single electrodes

Autonomous control of microfluidic transport was realized using electrowetting-based valves consisting of gold and zinc areas connected each other. Other external instruments such as potentiostats were not necessary for operation. The valve region surrounded by walls of gold and poly(dimethylsiloxane) (PDMS) became hydrophilic when an electrolyte solution reached the zinc electrode. As a result, the valve opened. The valve worked even if the electrodes were in independent microchannels. Mixing of solutions and detection of epinephrine were carried out using the integrated valves.