Easy Science
Easy Science
  • Dong-Pyo, Kim Professor, CE
  • 승인 2013.03.06 19:13
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Microfluidic System for Better Chemical Process
Lab-on-a-chip is a device that allows laboratory experiments to be conducted on its nail-sized body, which is made possible by fine circuit-based semiconductor technology, as well as nanotechnology and bioengineering technology. In 1990s, microfluidics-related MEMS (Micro Electro Mechanical System) technology leads to the ability to handle a few nanoliters of liquid specimen on a chip. As its name suggests, it means a lab in a chip or a lab on a chip, in which micro-sized devices have been mainly used at three major fields of biological, analytical and chemical parts to develop the next generation diagnostic and analytical equipment, microreactors, respectively. At first, biochip and cell chip, and upgraded versions of DNA chip and protein chip as biological devices of lab-on-a-chip can conduct fast and accurate experiments only with a very small amount of specimen or sample through automated analytical process; they are capable of highly efficient on-site analysis and diagnosis essential in a number of fields such as medicine, bioengineering and environmental sciences. Alternatively, microreactors based on lab-on-a-chip can conduct pre-treatment, transfer, reaction, separation, and analysis inside microchannels, resulting in short reaction time and good yield due to high surface-to-volume ratio.
However, microreactors that have so far been built from glass, Si, metallic substances through semiconductor manufacturing technology are expensive and difficult to manufacture, so they could not be broadly used in many research fields of chemistry and chemical engineering. About twenty years ago, Harvard University Prof. Whiteside developed a cheap and easy-to-manufacture lab-on-a-chip using a silicone rubber polymer polydimethylsiloxane (PDMS), and it is now widely used for biological fields as biochip and cell chip. PDMS chips are cheap and can be easily produced, but they cannot be used for organic chemical process at elevated temperatures due to their low stability against organic solvents and low thermal stability. Despite these circumstances, there has been nearly no attempt to develop new materials based microreactors, which delays the progress far behind the biochip field. Therefore, the Center of Applied Microfluidic Chemistry (CAMC) led by Prof. Dong-Pyo Kim strives to find economical ways to produce user-friendly microreactors having a variety of functions and designs, with new materials that have never been used for microreactors.
Upon hearing about chemical experiments, most people generally picture a scientist who wears a white lab gown with a glass beaker and flask in hands doing experiments. Such conventional reactors as a flask have been used for 200 years, but inconveniently they are likely to produce different results from the same chemical reaction because reaction conditions (temperature, concentration, element ratio) can hardly be controlled. Furthermore, it is somewhat dangerous that explosives and toxic compounds must be handled. Researchers are possibly exposed to safety accidents. Our research center has developed an efficient microreactor system and process that enable explosive or toxic substances to be generated, purified, separated, and reacted in a safe manner; the dual-channel system in it has a bottom-channel where toxic gas compounds are generated and automatically purified by passing through separating membrane, and top-channel where non-toxic and useful chemicals are produced by reaction with the purified toxic reagent from the bottom channel. In the system, the integrated chemical processes were demonstrated in the very small and confined space within several minutes. This chemical system is safe and environment-friendly and can solve the social problems arising from the matter of storage, transport, and leakage of toxic substances. In addition, our center focuses on the development of substitute energy for petroleum using environmental-friendly and renewable biomass resources, namely biorefinery process technology to produce valuable chemicals from biomass for the replacement of petroleum. Specifically, we are trying to find lab-on-a-chip technology that is useful to produce lipid oil (TAP; triacylglycerol) on a large scale through efficient cultivation and harvest of microalgae in the base of high throughput screening concept.
In general, lab-on-a-chip technology is a key technology to develop biomedical chips used for early diagnosis of a range of diseases. When integrated with biotechnology, electronic engineering, and IT technology, it can create a whole new industry. For example, point-of-care device has come into the spotlight as health-care industry expanded. It can automatically analyze a drop of blood on a chip and send the analysis result directly to the doctor; it is expected to connect to ubiquitous health-care or home-care systems. The device is able to analyze not only blood or other bodily materials but also a small amount of chemicals, and so its marketability is expected to increase remarkably in high-tech and environmental industries. We may participate in the development of organs-on-a-chip, which has similar environments to human organs in itself and allows pre-clinical trials of drugs. If the organs-on-a-chip technology is put into practice, drugs would be safely tested with no argument on ethical problems of animal testing, not to mention that it is highly economical.
Currently, our lab, Center of Applied Microfluidic Chemistry (CAMC), consists of six post-doctoral researchers, four Ph.D. candidates, five students in M.S.-Ph.D. integrated program, and two undergraduate students. The center was selected as one of the Creative Research Initiative labs for long-term support from 2008 to 2017 and has been conducting research on a variety of topics related to lab-on-a-chip technology.