本研究設計並完成一種具有多層電極與三維微結構的介電泳晶片，目的達成分類、捕捉、與操控微粒子之最佳效果；在製程方面，利用微機電製程建立陣列式電極與三維微結構，並以負介電泳力(Negative Dielectrophoresis force, N-DEP Force) 作為操控之媒介。有別於平面式的介電泳電極設計，本研究使用上、中、下三層電極，可以個別施加不同大小與相位的電子訊號，三維結構之部分以SU-8 製作。利用週期性的電極分布與三維結構來扭曲空間中的電場，形成縱向不均勻電場，得以捕捉與操縱懸浮於微流管道中的粒子。此外，為達到單顆粒子分離之需求，以粒子的尺寸去設計適合的光罩，製作出恰能容納單顆粒子的構造。
理論與模擬部分，使用商用軟體模擬三種架構之介電泳力與抓取趨勢。實驗結果顯示，此晶片若在三層電極施加不同的電壓訊號 (施以相位落後)，可在溶液中有效地操控乳膠粒子，並加強抓取能力，且此操控效能令晶片具有重複使用性；此外，本文也探討不同尺寸微粒子的導電性，進而了解在何種頻率下可產生最大的負介電泳力而達到最佳之抓取效果。本研究提供以介電泳力操控粒子之設計準則與製程範例。

This study investigates new types of dielectrophoretic (DEP) chips which consist of arrayed electrodes and 3D microstructures. The goal is to optimize the sorting, trapping, and manipulating ability of beads. The underlying operational principle is based on negative-dielectrophoresis force.As different from conventional ones using only planar electrodes, these new DEP chips consist of ITO top and bottom electrodes, an arrayed Au middle electrode, and an arrayed SU-8 3D microstructure. In order to achieve single-bead manipulation, the size of the SU-8 3D microstructure array matches the size of the beads. It is shown that such a 3D structure not only
yields a non-uniform electric field for DEP trapping but also enhances the capability of positioning and immobilization of the trapped beads.
In theoretical analysis and simulation, Comsol Multiphysics is applied to simulate the DEP forces in these chips. In experiments, the results show the chips can successfully trap or manipulate beads by applying different electrical voltage signals with phase angles on the triple layer electrodes. In order to realize the optimum frequency to operate DEP force, we also investigate the electrical conductivity at different particle sizes.
In summary, we fabricate new DEP chips with improving capability of sorting, trapping, and manipulating beads. The design, analysis, and fabrication processes are all discussed in details.

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