癌症是影响人类健康的重大疾病之一, 如何快速、方便地分离癌细胞已经成为制约临床医学和科学研究的重要问题。本文将磁珠技术与MEMS技术相结合, 提出了一种等边三角排列的N i微磁柱结构, 在磁场作用下使用CD326免疫磁珠捕获结肠癌细胞。本文对MEMS细胞捕获芯片进行了设计、加工和封装, 采用该芯片对与磁珠结合的结肠癌细胞进行了捕获, 0. 1m l/h流速下捕获效率达92%,证明该芯片具有对结肠癌细胞的捕获能力。

Microfluidics has been considered as a potential technology to miniaturize the conventional equipments and technologies. It offers advantages in terms of small volume, low cost, short reaction time and high-throughput. The applications in biology and medicine research and related areas are almost the most extensive and profound. With the appropriate scale that matches the scales of cells, microfluidics is well positioned to contribute significantly to cell biology. Cell culture, fusion and apoptosis were successfully performed in microfluidics. Microfluidics provides unique opportunities for rare circulating tumour cells isolation and detection from the blood of patients, which furthers the discovery of cancer stem cell biomarkers and expands the understanding of the biology of metastasis. Nucleic acid amplification in microfluidics has extended to single-molecule, high-throughput and integration treatment in one chip. DNA computer which is based on the computational model of DNA biochemical reaction will become practice from concept in the future. In addition, microfluidics offers a versatile platform for protein-protein interactions, protein crystallization and high-throughput screening. Although microfluidics is still in its infancy, its great potential has already been demonstrated and will provide novel solutions to the high-throughput applications.

Microfluidic chips were designed and fabricated to capture cells in a relative small volume to generate the desired concentration needed for analysis. The microfluidic chips comprise 3D cell capture structures array fabricated in PDMS. The capture structure includes two layers. The first layer consists of spacers to create small gap between the upper layer and glass. The second layer is a sharp corner U-shaped compartment with sharp corners at the fore-end. And another type capture structure with Y-shaped fluidic guide has been designed. It was demonstrated that the structures can capture cells in theory, using Darcy-Weisbach equation and COMSOL Multiphysics. Then yeast cell was chosen to test the performance of the chips. The chip without fluid guides captured approximately 1.44×105 cells and the capture efficiency was up to 71%. And the chip with fluid guides captured approximately 5.0×104 cells and the capture efficiency was approximately 25%. The chip without fluid guides can capture more cells because the yeast cells in the chip without fluid guides are subject to larger hydrodynamic drag force.

The nuclear magnetic resonance (NMR) probe has great influence on signal transmission and reception in NMR technology applications. In this paper, we present a design, fabrication, and test of an NMR probe comprised of a multilayer planar microcoil with a polydimethylsiloxane (PDMS) microchannel. First, geometric parameters of the probe are determined through theoretical analysis. Second,based on a glass substrate, the multilayer planar microcoil is manufactured using repeated photolithography and electroplating processes. During the fabrication process,the polyimide layer is used to package the coil, and the PDMS interlayer is used to adjust the distance from centerlines between the coil and the sample chamber. Third,the resistance and the quality factor of the coil are found to be 1.2158 X and 7.217, respectively, at a Larmor frequency of 28.1 MHz. Finally, the NMR probe is tested in an NMR experiment. The transverse relaxation time T2 for the solid PDMS is 20.6 ± 0.4 ms, which is in agreement with 21.1 ± 0.2 ms obtained by a Bruker Minispec MQ60.Results show that the design and fabrication of this NMR probe are feasible for time-domain NMR applications.

设计了一种新型的脑电图干电极, 主要用于采集脑电信号以进行基于脑电图的警觉度分析, 替代传统的湿电极. 采用柔性衬底微电子机械系统( MEMS) 加工技术, 在柔性衬底上制备出具有化学稳定性与生物相容性的微针状干电极阵列. 通过铜牺牲层实现干电极微针的悬臂梁结构, 利用聚二甲基硅氧烷( PDMS) 剥离层实现器件从玻璃基底的完全释放, 并经平面电极的多层组装实现了立体电极阵列. 实验中干电极以聚酰亚胺作为柔性衬底, 其针端及导线部分材料为镍, 针端部分表面镀金. 采用Neuroscan 的脑电信号采集放大器对干电极性能进行了测试, 测得阻抗约为10k 8, 其时域和频域信号与传统湿电极基本一致. 所制备的干电极成品率高、尺寸小、屏蔽佳、装配简单、可靠性好、机械强度大, 符合快速、无痛的脑电信号采集要求。