Browsing by Author "Liu, Ming-Huei"

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Concentration of Magnetic Beads Utilizing Light-Induced Electro-Osmosis Flow
(2011-10-01)
Yang, Shih-Mo
;
Harishchandra, Punde Tushar
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Yu, Tung-Ming
;
Liu, Ming-Huei
;
Hsu, Long
Magnetic beads are widely utilized for separating biomolecules, DNA and RNA. Traditionally, bulk magnet is utilized for manipulation these particles but when it comes to microscale bulk magnet is not the efficient method. Here, we utilize an organic photoconductive material, TiOPc, to generate light-induced electro-osmosis flow on chip. The fabrication process is convenient to be handled by the researchers and biologists without cleanroom IC fabrication facility. When specifically designed light pattern is projected onto the TiOPc substrate, the conductivity of the organic material layer within the illuminating region increases and the charges are locally assembled on its surface to form a virtual electrode. With an external ac voltage of 5 Vpp at 10 kHz, numerous magnetic beads are attracted from the nonilluminating region toward the center of light-pattern illuminating region. Driven by the moving light image, the grouped magnetic beads can be manipulated and merged in a desired way or direction. The light manipulation process provides a flexible and convenient approach for in vitro control of magnetic beads. We expect that this light-driven technology would display a multifunctional platform for manipulation of microparticles.
Integration of organic opto-electrowetting and poly(ethylene) glycol diacrylate (PEGDA) microfluidics for droplets manipulation
(2013-04-01)
Yu, Tung-Ming
;
Yang, Shih-Mo
;
Fu, Chien-Yu
;
Liu, Ming-Huei
;
Hsu, Long
This paper reports a fabrication technology which integrates organic opto-electrowetting (OEW) with PEGDA-based microfluidics between stacked ITO glass chips for droplets generation and manipulation. Organic OEW can be realized by using titanium oxide phthalocyanine (TiOPc) as a photoconductive layer. Optical images can be projected on an organic OEW area to induce the local virtual electrodes which reduce the surface energy for actuating droplets. Low-molecular-weight (LMW) PEGDA (poly(ethylene) glycol diacrylate) material is used to form stable and biocompatible microchannels between the stacked ITO glass chips by UV photopolymerization process. PEGDA-based microfluidics provides a simpler way to enhance droplets applications in organic OEW. We demonstrate (1) the droplet formation in PEGDA microstructure, (2) the motion of droplet-in-air and droplet-in-oil operated by TiOPc OEW in this platform. This technology requires only spin-coating and UV exposure and is more cost-effective than previous methods. (C) 2011 Elsevier B.V. All rights reserved.
ORGANIC PHOTOCONDUCTIVE DIELECTROPHORESIS BY USING TITANIUM OXIDE PHTHALOCYANINE FOR MICRO-PARTICLES MANUPULATION
(2010)
Yu, Tung-Ming
;
Yang, Shi-Mo
;
Huang, Hang-Ping
;
Ku, Meng-Yen
;
Tseng, Sheng-Yang
This paper reports our updating development for the organic photoconductive dielectrophoresis (OPDEP) by using titanium oxide phthalocyanine (TiOPc) material for the manipulation of micro-objects. The advantages of organic photoconductive material include non-toxicity, low cost, easy coating fabrication, flexibility, panchromaticity and high photosensitivity [1]. TiOPc has the high photoconductivity and the optical absorptions in the near infrared region (550 - 850 nm) to be a candidate of the light-sensitive charge generation layer. OPDEP chip is easily mass-produced by using a spin-coating process. Here, we demonstrate two kinds of the manipulations of micro-particles on our OPDEP chip. Firstly, the trapping and movement of single micro-particle is achieved by the ring shaped virtual electrode. Secondly, the steel rim shaped virtual electrode is designed to rotate micro-particles and characterize the OPDEP induced force.