title: PMMA/PDMS valves and pumps for disposable microfluidics.
abstract: Poly(methyl methacrylate) (PMMA) is gaining in popularity in microfluidic devices because of its low cost, excellent optical transparency, attractive mechanical/chemical properties, and simple fabrication procedures. It has been used to fabricate micromixers, PCR reactors, CE and many other microdevices. Here we present the design, fabrication, characterization and application of pneumatic microvalves and micropumps based on PMMA. Valves and pumps are fabricated by sandwiching a PDMS membrane between PMMA fluidic channel and manifold wafers. Valve closing or opening can be controlled by adjusting the pressure in a displacement chamber on the pneumatic layer via a computer regulated solenoid. The valve provides up to 15.4 microL s(-1) at 60 kPa fluid pressure and seals reliably against forward fluid pressure as high as 60 kPa. A PMMA diaphragm pump can be assembled by simply connecting three valves in series. By varying valve volume or opening time, pumping rates ranging from nL to microL per second can be accurately achieved. The PMMA based valves and pumps were further tested in a disposable automatic nucleic acid extraction microchip to extract DNA from human whole blood. The DNA extraction efficiency was about 25% and the 260 nm/280 nm UV absorption ratio for extracted DNA was 1.72. Because of its advantages of inexpensive, facile fabrication, robust and easy integration, the PMMA valve and pump will find their wide application for fluidic manipulation in portable and disposable microfluidic devices.
authors.affiliation: Department of Chemical Biology, Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, State Key Laboratory for Physical Chemistry of Solid Surface, and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, 361005, China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Zhang
authors.forename: Shuichao
authors.initials: S
authors.lastname: Lin
authors.forename: Chunming
authors.initials: C
authors.lastname: Wang
authors.forename: Jia
authors.initials: J
authors.lastname: Hu
authors.forename: Cong
authors.initials: C
authors.lastname: Li
authors.forename: Zhixia
authors.initials: Z
authors.lastname: Zhuang
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Zhou
authors.forename: Richard A
authors.initials: RA
authors.lastname: Mathies
authors.forename: Chaoyong James
authors.initials: CJ
authors.lastname: Yang
mesh_terms: D004247:DNA / Q000097:blood / Q000235:genetics / Q000302:isolation & purification; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004209:Disposable Equipment; D004867:Equipment Design; D006801:Humans; D056656:Lab-On-A-Chip Devices; D008567:Membranes, Artificial; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry; D016133:Polymerase Chain Reaction; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D004129:Dimethylpolysiloxanes; D008567:Membranes, Artificial; C013830:baysilon; D010126:Ozone; D004247:DNA; D019904:Polymethyl Methacrylate