Design and fabrication of an electrochemically actuated microvalve

A microfluidic valve based on electrochemical (ECM) actuation was designed, fabricated using UV-LIGA microfabrication technologies. The valve consists of an ECM actuator, polydimethylsiloxane (PDMS) membrane and a micro chamber. The flow channels and chamber are made of cured SU-8 polymer. The hydrogen gas bubbles were generated in the valve microchamber with Pt black electrodes (coated with platinum nanoparticles) and filled with 1 M of NaCl solution. The nano particles coated on the working electrode helps to boost the surface-to-volume ratio of the electrode for faster reversible electrolysis and faster valve operation. To test the functionality of the microvalve, a simple micropump based on ECM principle was also integrated in the system to deliver a microscopic volume of fluid through the valve. The experimental results have showed that an approximately 300 μm deflection of valve membrane was achieved by applying a bias voltage of −1.5 V across the electrodes. The pressure in the valve chamber was estimated to be about 200 KPa. Experimental results proved that the valve can be easily operated by controlling the electrical signals supplied to the ECM actuators.

[1]  Yoo,et al.  An electrochemical impedance measurement technique employing Fourier transform , 2000, Analytical chemistry.

[2]  Wouter Olthuis,et al.  A closed-loop controlled electrochemically actuated micro-dosing system , 2000 .

[3]  Steven A. Soper,et al.  Fabrication and test of an electrochemical microactutor , 2006, SPIE MOEMS-MEMS.

[4]  Ren Yang,et al.  A numerical and experimental study on gap compensation and wavelength selection in UV-lithography of ultra-high aspect ratio SU-8 microstructures , 2005 .

[5]  Hiroaki Suzuki,et al.  Integrated microfluidic system with electrochemically actuated on-chip pumps and valves , 2003 .

[6]  Wanjun Wang,et al.  Microfabrication of pre-aligned fiber bundle couplers using ultraviolet lithography of SU-8. , 2006, Sensors and actuators. A, Physical.

[7]  Chong H. Ahn,et al.  Institute of Physics Publishing Journal of Micromechanics and Microengineering a Review of Microvalves , 2022 .

[8]  Juan G. Santiago,et al.  A review of micropumps , 2004 .

[9]  Steven A. Soper,et al.  Out-of-plane microlens array fabricated using ultraviolet lithography , 2005 .

[10]  Wanjun Wang,et al.  Design and UV-LIGA microfabrication of an electro-statically actuated power relay , 2006 .

[11]  P. Hesketh,et al.  A microfabricated electrochemical actuator for large displacements , 2000, Journal of Microelectromechanical Systems.

[12]  Hiroaki Suzuki,et al.  A reversible electrochemical nanosyringe pump and some considerations to realize low-power consumption , 2002 .

[13]  Cristina Neagu,et al.  An electrochemical active valve , 1997 .

[14]  Yu-Chong Tai,et al.  An integrated LC-ESI chip with electrochemical-based gradient generation , 2004, 17th IEEE International Conference on Micro Electro Mechanical Systems. Maastricht MEMS 2004 Technical Digest.