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Early do-it-yourself microf luidics in China Legos and Tygon tubing are tools of the trade when specialized equipment isn’t available.
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(A) LI CHEN; (B) WEN-BIN DU
ticated fabrication equipment, says decade ago, the micro-total (a) (b) Dasgupta. “But they more than analysis system (µTAS) was make up for it in their creativity, an exciting new area of discovery imagination, and the ability to get for researchers in the U.S. and around obstacles,” he says. Europe. But because nobody in A stroll through Fang’s lab ilChina had any successful experilustrates what Dasgupta means. ence with it, Zhaolun Fang was One can see very few commercial facing a big challenge when he instruments but many lab-built decided to involve his group at instruments and tools. Students the Northeastern University in (a) Wen-Bin Du, a Ph.D. student in Fang’s lab, works on a work in crowded lab space and Shenyang in this research. high-throughput, flow-injection analysis system that uses LIF use Lego blocks and parts from Despite the attractive prospects detection. (b) A homemade glass chip used in the system. A old instruments to create their of the new field, most researchers 1-yuan coin is in the foreground. own experimental equipment. in China thought that the work A major boost to the development of at Zhejiang University (China). This would be very costly and that obtaining university had excellent microfabrication microfluidic systems in China occurred sufficient funding would be difficult. Bein 2002, when the National Natural Scifacilities, and various groups with excause the Fang group’s equipment was ence Foundation of China decided to pertise in microelectronic mechanical meager at the time, their first attempts launch a major project called Basic Resystems (MEMS) were already there. at producing microfabricated chips were search on Microfluidic Bioanalytical SysFang and his second group lacked the more than discouraging; they filled a tems. The project is headed by Fang, money to buy sophisticated equipment large wooden case with broken glass and 10 major Chinese universities and for MEMS, so they started to design from unsuccessful efforts. research institutes of the Chinese Acadand build their own LIF detectors and Although they couldn’t reproduce emy of Sciences participate. The total multiterminal, high-voltage power supthe microfabrication techniques that ply units; they also tried fabricating glass funding over 4 years is $900,000, of they were reading about, they wanted which Fang’s groups receive about onechips by controlling the local environto get some feeling for µTAS devices. fourth. Though the amount may seem So, they added a silica capillary to a glass ment under a continuous flow of tap large, it really is not enviable, Fang says, microscope slide and made two side arms water and, later, demineralized water. “particularly compared to well-funded A year later, they successfully develfrom Tygon tubing. They introduced groups in developed countries, or even oped their first microfabricated glass samples through the side arms with a compared to other better-funded fields chip for CE with LIF detection for the sequential injection system with a splitin China.” Yet, he adds, the support separation of amino acids. Later, they flow approach and added laser-induced came at a critical time and was an “efcoupled a flow-injection system to it to fluorescence (LIF) detection. The 1999 fective spur” for further innovation. paper that described this work was noted achieve continuous sample introduction These days, Fang reports, “there are via a flow-through, on-chip reservoir on Web of Science as the first one pubapproximately 25 groups around China lished by a group in China with the key- (Anal. Chem. 2002, 74, 1223 –1231). conducting research in micro-total analyword “microfluidics” (Anal. Chim. Acta Further refinement of the fabrication procedure proved that glass microfluidic sis systems.” Albert van den Berg of the 1999, 390, 27– 37). Sandy Dasgupta of chips could be fabricated and bonded at University of Twente (The Netherlands) Texas Tech University fondly dubbed notes, “There is definitely an increasing room temperature. The chips could be this design the “poor man’s chip”. It number of submitted papers [from China] became the basic platform for the devel- produced for $20 –30 each by students in µTAS; what is more important, howevin their own labs. The students could opment of a series of other microfluidic er, is that the overall quality is increasing.” design and fabricate the chips in just systems with amperometric, chemilumiFang is optimistic about future develone day (Anal. Chem. 2004, 76, 5597– nescent, and UV detection (Fresenius’ J. opments. “After all,” he says, “innova5602). “A normal price for a glass chip Anal. Chem. 2001, 370, 978–983). in the USA or Europe would be around tive research in microfluidics need not At the end of 1999, Fang decided to be that costly, provided that creativity is $100–200,” says Fang. set up a second group to focus excluput in the first place.” a The group operates in a crowded lab sively on developing µTAS, this time at —Thanh Wang and does not have access to much sophisthe Institute of Microanalytical Systems © 2006 AMERICAN CHEMICAL SOCIETY
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