Microfluidics is a technology that involves the precise manipulation of fluid flow on the microscale. It emerged in the 1980s and since then has seen a fast development and wide application in the fields of DNA chips, instant diagnosis, lab-on-a-chip technology, etc.
Microfluidic chip, also known as “lab-on-a-chip”, is the main platform on which microfluidics technology is carried out, integrating laboratory functions such as sample preparation, reaction, separation, detection, etc. in biological, chemical and medical analysis on a single micrometer scale chip to achieve automated analysis. Microfluidic chip has the advantages of small sample consumption, fast detection, easy operation, multi-function, small size, portability, etc. and has shown a great potential in the fields of biology, chemistry and medical science, etc. In recent years, it has grown into an emerging research field at the intersection of biology, chemistry, medicine, fluidics, electronics, material science, mechanics, etc.
PDMS is abbreviated for polydimethylsiloxane. With the advantages of convenience, low cost and biocompatibility, it has been widely used in manufacturing and processing of microfluidics chips. Form certain patterns on the silicon substrate by employing soft lithography techniques; after demolding and curing, micro scale channels are formed. After hydrophilic surface treatment, PDMS binds to the glass permanently to form microfluidics chip. This technique can be used to fabricate microchannels, micromixers, micropumps, microvalves, etc. and has been used in the development of various functional chips.
Silica and glass have good optical properties and can be used in processing and fabricating of microfluidics chips by means of lithography and etching, etc. Main procedures in chip processing include: coating, exposure, development, dissolution, decoating, etc. The processing environment and procedures have direct impact on the quality of the chip; therefore, strict techniques are required to be followed to ensure high microstructure precision and to avoid burrs and manufacturing defects.
Thin film deposition technology involves applying certain thin film over the substrate surface. It may either serve as a medium film for protection, passivation or insulation or form a metal conducting film for electrode lead and component interconnection. Thin film growth technology falls into two categories: direct growth and indirect growth. The former includes vapor phase epitaxy, chemical phase deposition, thermal oxidation, etc.; the latter involves transferring primary materials onto the substrate and includes liquid phase epitaxy, physical deposition, etc.
Microfluidics technology is playing a significant role in biomedical fields such as clinical diagnostic instruments, in vitro bionic models, etc. It is especially widely used in precision medicine and molecular diagnostics. Agilent Technologies，Bio-Rad，Thermo Fisher Scientific all launched clinical diagnostic products based on microfluidics technology.
In the 13th Five Year Plan on Science and Innovation approved and issued in July, 2016, Premier Li Keqiang clearly pointed out “to make major breakthroughs in microfluidics and single molecule detection, to develop automated nucleic acid detection products and to develop diagnostic reagents for early diagnosis of major diseases and high precision diagnostic products suitable for primary medical institutions”.
In December, 2016, Beijing GenomeWay Medical Engineering Co., Ltd. and Shanghai Institute of Microsystem and Information Technology of Chinese Academy of Sciences signed a memorandum of cooperation on industrialization of microfluidics technology. Through signing this agreement, Shanghai Institute of Microsystem and Information Technology licensed four patented technologies to Beijing GenomeWay Medical Engineering Co., Ltd. Both sides, through joint efforts, would fully mobilize all their advantages and resources to promote industrialization of microfluidics technology in clinical detection and make contributions in developing new and highly sensitive in vitro molecular diagnostic instruments and reagents in medical laboratory science.