一般傳統微生物檢測法雖已可提供精確的結果，但此過程耗時且費成本，故發展精確且快速分離技術的檢測工具，對於感染性致病菌的診斷仍極為重要的。基於此，擁有快速檢測且能結合多種功能性的交流電動晶片元件與其系統，極被寄予厚望。其中介電泳晶片是一種較常用的分離技術；其原理主要是透過金屬電極排列形成非均勻電場，來誘導微粒子產生固液界面之間的極化現象，因而促使溶液中之微粒趨往高或低電場區域移動，並藉此達到操控或分離粒子的功能。本研究研發一種無鍍有微型電極式的交流介電泳（EDEP）晶片，用以分離微管道的微粒子。在這以polydimethylsiloxane (PDMS)材質灌模製成的EDEP晶片的微管道中設計了一對三角形結構， 依此幾何結構來產生非均勻電場。我們利用FEMLAB®模擬軟體的數值分析，來取得較佳化的電場梯度分佈和結構設計，並經實驗操作予以驗証，所得結果有三點：(1) 將2.2 m和6.5 m的latex進行測試，發現可在去離子水的溶液中，以10 kHz和400 Vp-p/mm的交流電信號，將2.2 m的latex吸附至結構尖端(正介電泳力)，然而6.5 m的latex可被排斥至結構尖端之外區域(負介電泳力)。(2) 在微生物檢測應用方面，主要應用於菌血症的模擬實驗，於調配好的等張溶液中，以10 kHz頻率和500 Vp-p/mm，即可成功的分離出細菌和血球的混合樣本，此時血球會被排斥到弱電場之區域，細菌則吸附至強電場區。(3) 利用交流電訊號的頻率變化，來進行微粒子的操控，可使微粒子透過彼此的作用力，產生結構排列、渦流混合，細胞胞解等功能。由上述三項結果顯示，利用此介電泳分離技術的研究，能成功的分離出不同尺寸的latex、和細菌與血球混合樣本，及利用不同頻率的切換來進行微粒子的操控。未來此技術成熟之後，將可運用於更多的方面，並可結合到光學檢測裝置，以做更精確微生物鑑定，來提昇微生物檢測品質和時效性。

The traditional bio-diagnosis procedure is relatively time-consuming, although it can provide accurate results. So, the development of the precise and rapid separation technology is the main aim to provide a better and more efficient bio-diagnosis in clinical microbiology. Based on such a motivation, some of the AC electrokinetic technologies have been developed due to rapidly diagnosis that can be integrated into functioning devices for variety of applications. Among these techniques, dielectrophoretic (DEP) chip is a common method for the the application of biosamples separation. In classical DEP theories, it describes that the non-uniform electric field maded by metallic electrode aligenment product the ploarization in the solid-liquid interfacethe and it make dielectric particles to move the high or low intensitial regions of electric fields, and then to be manipulated and separated. In this research, we designed a new DEP chip without metallic electrode deposition and designed a triangular-shaped structure to create a non-uniform electric field in the microfluidic channel chip fabricated by polydimethylsiloxane (PDMS). So we called this new type DEP chip as electrodeless DEP (EDEP). We simulated by FEMLAB® to get the optimum distribution of electric field gradient. First, we determined that 2 m and 6.5 m latex particles could be separated at 10 kHz and 400 Vp-p/mm in deionized water. On the other hand, we also simulated bacteremia diagnosis to separate the mix sample of bacteria and blood cell at 10 kHz and 500 Vp-p/mm in physiological buffer. Finally, we manipulated the particles by interacting, mixing and cell lysing by AC field variant. In the future, the EDEP chip will integrate an optical technique to indenify the diseases and improve clinical diagnosis.

[1] 黃錦城,綜論微生物快速檢測技術,食品工業, 35(2003)19-35
[2] 陳建人, 微機電系統技術與應用, 國科會精儀中心出版, (2004)
[3] 馬立人,蔣中華, 生物晶片, 九州圖書文物有限公司, (2003)
[4] Peter R. C. Gascoyne, J. Vokoukal, Particle separation by dielectrophoresis, Electrophoresis, 23(2002)1973-1983
[5] T. B. Jones, Electromechanics of particles, Cambridge University Press, 1995
[6] H. Morgan, N. Green, AC electrokinetics - colloids and nanoparticles, Research Studies Press, 2003
[7] H. C. Chang, Electrokinetics:a viable microfluidic platform for miniature diagnostic kits,” Can. J. Chem. Eng., 84(2006)1-15
[8] J. Wu, Y. Ben, H. C. Chang, Particle detection by electrical impedance spectroscopy with asymmetric polarization AC electroosmotic trapping, Microlfuid. and Nanofluid., 1(2005)161-167
[9] N. G. Green, H. Morgan, Sub-micrometre AC electrokinetics, Proc IEEE Conference on Engineering in Medicine and Biology, 20(1998) 2974-2977
[10] M. Washizu, S. Suzuki, O. Kurosawa, T. Nishizaka, T. Shinohara, Molecular dielectrophoresis of biopolymers, IEEE Trans. Ind. Appl., 30(1994)835-843
[11] A. Ramos, H. Morgan, N. G. Green, A. Castellanos, AC electric-field induced fluid flow in microelectrodes, J. Colloid Interface Sci., 217(1999)420-422
[12] N. G. Green, A. Ramos, A. Gonzalez, A. Castellanos, H. Morgan, Electrothermally induced fluid flow on microelectrodes, J. Electrost., 53(2001)71-87
[13] A. D. Goater, R. Pethig, Electrorotation and dielectrophoresis, Parasitology, 117(1998)S177-S189
[14] Y. Ben, H. C. Chang, Nonlinear smoluchowski slip velocity and micro vortex generation, J. Fluid. Mech., 461(2002)229-238
[15] S. Thamida, H. C. Chang, Nonlinear electrokinetic ejection and entrainment due to polarization at nearly insulated wedges, Phys. Fluids, 14(2002)4315-4328
[16] M. Z. Bazant, M. Squires, Induced-charge electrokinetic phenomena: Theory and microfluidic applications, Phys. Rev. E., 92(2004)
066101-1-066101-4
[17] J. Levitan, S. Devasenathipathy, V. Studer, Y. Ben, T. Thorsen, T. M. Squires, M. Z. Bazant, Experimental observation of induced-charge electro-osmosis around a metal wire in a microchannel, Colloid. Surface., A 267(2005)122-132
[18] M. Washizu, T. Nanba, S. Masuda, Handling of biological cells using fluid integrated circuit, IEEE T. Ind. Appl., 25(1990)352-358
[19] C. F. Chou, J. O. Tegenfeldt, O. Bakajin, S. S. Chan, E. C. Cox, N. Darnton, T. Duke , R. H. Austin, Electrodeless dielectrophoresis of single- and double-stranded DNA, Biophys. J., 83(2002)2170-2179
[20] C. F. Chou, F. Zenhausern, Electrodeless dielectrophoresis for micro total analysis systems, IEEE. Eng. Med. Biol. Mag., 22(2003)62-67
[21] Y. Fintschenko, B. A. Simmons, B. H. Lapizco-Encinas, E. B. Cummings, Insulating post electrodeless dielectrophoresis for the concentration of bacteria, Proceedings of µTAS 2003, 1(2003)65-68
[22] B. H. Lapizco-Encinas, B. A. Simmons, E. B. Cummings, Y. Fintschenko, High-throughput electrodeless dielectrophoresis of viruses in polymeric microdevices, Proceedings of TAS 2003, 1(2003)607-610
[23] B. H. Lapizco-Encinas, B. A. Simmons, E. B. Cummings, Y. Fintschenko, Dielectrophoretic concentration and separation of live and dead bacteria in an array of insulators, Anal. Chem., 76(2004)1571-1579
[24] L. Tang, M. S. Sheu, T. Chu, Y. H. Huang, Anti-inflammatory properties of triblock siloxane copolymer-blended materials, Biomaterials, 20(1999) 1365-1370
[25] N. G. Green, H. Morgan, Dielectrophoretic investigations of sub-micrometre latex spheres, J. Phys. D: Appl. Phys., 30(1997) 2626–2633
[26] 蕭孟芳,圖解醫學微生物學與感染症, 合記圖書,(2002).
[27] 曾岐元, 最新病理學, 匯華圖書,(2000)
[28] 陳宜君, 盧柏樑, 敗血症, 當代醫學, 25 (1998) 10-16
[29] F. P. Silveira, A. Marcosb, E. J. Kwak, S. Husain, R. Shapiro, N. Thai, K. R. McCurry, Bloodstream infections in organ transplant recipients receiving alemtuzumab: no evidence of occurrence of organisms typically associated with profound T cell depletion, J. Infect., 81(2006) 1361-1367
[30] S. Pongsunk, N. Thirawattanasuk, N. Piyasangthong, P. Ekpo, Rapid identification of burkholderia pseudomallei in blood cultures by a monoclonal antibody assay, J. Clin. Microbiol., 37(1999)3662-3667
[31] J. Cheng, E. L. Sheldon, L. Wu, M. J. Heller, J. P. O'Connell, Isolation of cultured cervical carcinoma cells mixed with peripheral blood cells on a bioelectronic chip, Anal. Chem., 70(1998)2321-2326
[32] X. F. Zhou, G. H. Markx, R. Pethig, I. M. Eastwood, Differentiation of viable and non-viable bacterial biofilms using electrorotations, Biochim Acta., 1245(1995)85-93
[33] A. Minerick, P. Takhistov, R. Zhou, H. C. Chang, Manipulation and characterization of red blood cells with AC fields in micro-devices, Electrophoresis, 24(2003)3703-3717
[34] H. Lu, M. A. Schmidt, K. F. Jensen., A microfluidic electroportation device for cell lysis, Lab Chip, 5(2005)23-29
[35] S. W. Lee, Y. C. Tai, A micro cell lysis device, Sensor. Actuat. A -Phys., 73(1999)74-79
[36] N. G. Green, H. Morgan, Dielectrophoretic investigations of sub-micrometre latex spheres, J. Phys. D: Appl. Phys., 30(1997) 2626-2633
[37] Z. Gagnon, H. C. Chang, Aligning fast alternating current electroosmotic flow fields and characteristic frequencies with dielectrophoretic traps to achieve rapid bacteria detection, Electrophoresis, 26(2005)3725-3737