An integrated microfluidic system with a check valve and a micropump based on electrochemical actuation was
designed and fabricated using UV-LIGA microfabrication technologies. The main components of the system include
two electrochemical (ECM) actuators, a polydimethylsiloxane (PDMS) membrane, and multi levels of covers. The
thickness of the membrane is 100 &mgr;m thick and the thickness of the PDMS structure is 1000 &mgr;m. Hydrogen gas bubbles
were generated from Pt black electrodes with 1M of NaCl solution in the valve chamber. Experimental results proved
that the system can be operated by controlling the electrical signals supplied to the ECM actuators.
This paper reports on the design, fabrication, and analysis of an electrochemical (ECM) microactuator. The driving mechanism of the ECM actuator is based on the reversible electrolysis process of water. The expansion and reduction of gas bubbles generated in a micro electrochemical chamber during a reversible electrolysis process can be used to provide a pressure difference in microlfuidic systems. The ECM actuator has a very simple design consisting of inlet/outlet channels, reservoirs, and electrochemical reaction chamber. The fluidic components of the ECM actuator were fabricated on a glass substrate using UV lithography of SU-8 using both Pt black and Ag/AgCl electrodes. The Pt black and Ag/AgCl coated electrodes were supplied with controlled electropotentials for active control of expansion and shrinkage of gas bubbles using reproducible electrochemical reactions. The theoretical volume change rate of gas
bubbles was simulated as a function of time using the ideal gas law and compared with the measured volume change. The results show that the simulation can be used to predict trends of the volume change by the electrochemical reactions and also, the device can serve as a promising microactuator for microfluidic applications.
The research work reported in this paper focuses on developing an electrochemical micropump and a DNA mixing and analysis system using the electrochemical pumps for actuation. The micropum consists of two swing-door check valves and an electrochemical pumping chamber. In the prototype system, two micropumps were used to deliver the reagents and DNA samples respectively. The SU-8 based UV-lithography process was used to fabricate the system on a glass substrate.