Hawkins Benjamin G, Smith A Ezekiel, Syed Yusef A, Kirby Brian J
Department of Biomedical Engineering, School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
Anal Chem. 2007 Oct 1;79(19):7291-300. doi: 10.1021/ac0707277. Epub 2007 Sep 1.
We present the development of a continuous-flow, "dielectrophoretic spectrometer" based on insulative DEP techniques and three-dimensional geometric design. Hot-embossed thermoplastic devices allow for high-throughput analysis and geometric control of electric fields via ridged microstructures patterned in a high width-to-depth aspect ratio (250:1) channel. We manipulate particles with dc-biased, ac electric fields and generate continuous-output streams of particles with a transverse outlet position specified by linear and nonlinear particle mobilities. We show, with simulation and experiment, that characteristic shape factors can be defined that capture the effects of constrictions in channel depth and that modulating the angle of these constrictions changes the resulting local DEP force. Microdevices are fabricated with an insulative constriction in channel depth, whose angle of incidence with the direction of flow varies continuously across the channel width. The resulting electric field gradients enable demonstration of a dielectrophoretic spectrometer that separates particles and controls their transverse channel position.
我们展示了一种基于绝缘介电泳（DEP）技术和三维几何设计的连续流“介电泳光谱仪”的开发。热压印热塑性装置允许通过在高宽深比（250:1）通道中图案化的脊状微结构进行高通量分析和电场的几何控制。我们利用直流偏置的交流电场操纵粒子，并通过线性和非线性粒子迁移率指定横向出口位置来生成连续输出的粒子流。我们通过模拟和实验表明，可以定义特征形状因子来捕捉通道深度收缩的影响，并且调节这些收缩的角度会改变产生的局部DEP力。微器件在通道深度处制造有绝缘收缩，其与流动方向的入射角在整个通道宽度上连续变化。由此产生的电场梯度使得能够展示一种介电泳光谱仪，该光谱仪可以分离粒子并控制它们在横向通道中的位置。
