Parallel valveless micropump with two flexible diaphragms

This paper presents a parallel dynamic passive valveless micropump, which consists of three layers-valve, diaphragm and electromagnetic coil. The valve is wetly etched in a silicon wafer, the diaphragm is a PDMS (polydimethyl siloxane) film spun on a silicon wafer with embedded permanent magnet posts, and the coil is electroplated on a silicon substrate. Under the actuation of the magnetic field of the coil, the flexible diaphragm can be displaced upwards and downwards. After analyzing magnetic and mechanical characteristic of the flexible membrane and direction-dependence of the diffuser, this paper designed a micropump. And the relative length (L/d) of the micropump’s diffuser is 4.An 7×7 array of permanent magnetic posts is embedded in the PDMS film. Two diaphragms work in an anti-step mode, which can relieve the liquid shock and increase the discharge of the micropump. ANSYS® and Matlab® are adopted to analyze the actuation effect of the coil and the flow characteristic of the micropump. Results show that when actuated under a 0.3A, 100Hz current ,the displacement of the diaphragm is more than 30μm, and the discharge of the micropump is about 6μL/s.

[1]  Torsten Gerlach.  Microdiffusers as dynamic passive valves for micropump applications , 1998 .

[2]  Arthur Brunnschweiler,et al.  The dynamic micropump driven with a screen printed PZT actuator , 1998 .

[3]  M. Nakano,et al.  Fabrication of NdFeB thick film magnets by high speed PLD method , 2003, Digest of INTERMAG 2003. International Magnetics Conference (Cat. No.03CH37401).

[4]  S. Timoshenko,et al.  THEORY OF PLATES AND SHELLS , 1959 .

[5]  M. Richter,et al.  A bidirectional silicon micropump , 1995 .

[6]  C. Liu,et al.  A novel micromachined magnetic membrane microfluid pump , 2000, Proceedings of the 22nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (Cat. No.00CH37143).

[7]  Jörg Müller,et al.  Numerical simulation and optimization of planar electromagnetic actuators , 1998 .

[8]  Jens Anders Branebjerg,et al.  Microfluidics-a review , 1993 .

[9]  Weisong Wang,et al.  Composite elastic magnet films with hard magnetic feature , 2004 .

[10]  Wenjin Zhang,et al.  Electroplated thick CoNiMnP permanent magnet arrays for micromachined magnetic device applications , 1996, Proceedings of Ninth International Workshop on Micro Electromechanical Systems.

[11]  G. Stemme,et al.  Micromachined flat-walled valveless diffuser pumps , 1997 .

[12]  Li Wang,et al.  Characteristics and fabrication of NiTi/Si diaphragm micropump , 2001 .

[13]  O. Jeong,et al.  Fabrication and test of a thermopneumatic micropump with a corrugated p+ diaphragm , 2000 .

[14]  Jin-Chern Chiou,et al.  Efficient magnetic microactuator with an enclosed magnetic core , 2002 .