Research On Microfabrication Technology Of Biochip

As a powerful technology for microelectronics semiconductor industry,microfabrication has made a significant contribution to the improvement of modernlife, and kept continuous innovation and rapid developement. However, theapplication of micro-processing technology is not limited to electronics, people intendto extend this technology to many areas, such as micro electro mechanical system(MEMS), micro optical mechanical system (MOMS), and biochip. Especially, due toits unique advantages, such as trace sample consumption, high efficiency, highsensitivity and environmental friendliness, biochips received worldwide attention.Despite a short history, biochips were expected to be a novel testing platform which isused to solve the problems with regard to human health, food safety and geneticengineering. The development of biochip depends on the state of the art of themicrofabrication to some extent, how to construct functional microchip for biologyuse by microfabrication is the key point. In this thesis I focused my work on thiscentral idea: I studied several microfabrication technologies, fabricated microchips,and attempted to apply the functional microchips for both fundamental and clinical usein biology and medical care. The main research contents are as follows:1. Combined with different microfabrication technology, we produced a kind ofmicrofluidic chip with real three-dimensional (3D) microstructure. Herein, toproduce3D microfluidic chip, we combined traditional photolithography andwet etching techniques with femtosecond laser fabrication, and successfullyfabricated a functional microfluidic chip for sieving microparticles and theirone-way passing. This method not only provides a solution to fast fabrication,but also demonstrates a novel way for functionalization of biochips: theingenious combination of microfabrication technology, and the innovativefunction.2. In this part of work, a biochip with a series of microelectrodes has beenrealized for controlling cell attachment and detachment dynamically. Bothcell attachment and detachment are normal cell behaviors and play asignificant role in many physiological processes, such as tumor metastasisand body development. In order to realize a system to control such cellbehaviors in vitro, we chemically modificated an electrode array produced bymicrofabrication, and as a functional biochip to control cell attachment and detachment dynamically. It can pattern cells in designed isolate electrodes,and selectively release some of them by applying a proper voltage. We regardthis biochip as a potential tool to the research on complicated diseases forhuman health.3. We developed a biochip system for liver cancer early detection, and thissystem is in the progress for clinical application. According to statistics,China possesses half of patients of liver cancers in the world as the highincidence country. In addition, there is no outward early symptom in livercancer, which is ignored easily by traditional methods, and it could not becured when fast developing in the terminal stage of cancer. Therefore, it isurgent to develop a new type of high-speed system for liver cancer earlydetection. During my Ph.D study, I fabricated a biochip for liver cancerdetection. Specifically, a functional microfluidic chip was fabricated and ismodified with special antibody inside. When the sample of peripheral bloodflowed in the chip, the antigen of circulating tumor cells will bind in theantibody of microfluidic chip to achieve fast detection, if there are some inthe sample. And the initial results of this chip have demonstrated itssensitivity and specificity for catch few circulating tumor cells. Furthermore,the clinical test of this chip is ongoing, and we believe this system will beapplied in clinical diagnosis in the near future.In conclusion, my main works are focused on the microfabrication ofmultifunctional biochip, and try to speed up the application of such biochip to fromfundamental study to clinical medicine. Based on biochip's numerous advantages,such as high throughput, low cost, less reagent, fast reaction and better observation, Ibelieve that the application prospect of biochip is enormous in the future. And I hope Ican contribute to the application of microfabrication technology in biochip area andproduce more functional biochips.