Browsing by Author "Chen, Hung-Po"

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Cell patterning via diffraction-induced optoelectronic dielectrophoresis force on an organic photoconductive chip
(2013)
Yang, Shih-Mo
;
Tseng, Sheng-Yang
;
Chen, Hung-Po
;
Hsu, Long
;
Liu, Cheng-Hsien
A laser diffraction-induced dielectrophoresis (DEP) phenomenon for the patterning and manipulation of individual HepG2 cells and polystyrene beads via positive/negative DEP forces is reported in this paper. The optoelectronic substrate was fabricated using an organic photoconductive material, TiOPc, via a spin-coating process on an indium tin oxide glass surface. A piece of square aperture array grid grating was utilized to transform the collimating He-Ne laser beam into the multi-spot diffraction pattern which forms the virtual electrodes as the TiOPc-coating surface was illuminated by the multi-spot diffraction light pattern. HepG2 cells were trapped at the spot centers and polystyrene beads were trapped within the dim region of the illuminated image. The simulation results of light-induced electric field and a Fresnel diffraction image illustrated the distribution of trapped microparticles. The HepG2 morphology change, adhesion, and growth during a 5-day culture period demonstrated the cell viability through our manipulation. The power density inducing DEP phenomena, the characteristics of the thin TiOPc coating layer, the operating ac voltage/frequency, the sandwiched medium, the temperature rise due to the ac electric fields and the illuminating patterns are discussed in this paper. This concept of utilizing laser diffraction images to generate virtual electrodes on our TiOPc-based optoelectronic DEP chip extends the applications of optoelectronic dielectrophoretic manipulation.
Light-driven manipulation of picobubbles on a titanium oxide phthalocyanine-based optoelectronic chip
(2011-04-11)
Yang, Shih-Mo
;
Yu, Tung-Ming
;
Huang, Hang-Ping
;
Ku, Meng-Yen
;
Tseng, Sheng-Yang
Microbubbles have a variety of applications in science and biological technology. Here, we demonstrate the manipulation of the picoliter gas bubble (picobubble) based on the optoelectronic-mechanism. The organic photoconductive material, titanium oxide phthalocyanine (TiOPc), was developed to make the light-sensitive substrate of this optoelectronic chip. The virtual electrodes are formed by projecting the dynamic light pattern onto TiOPc layer for generating the desired nonuniform electric field. The picobubble suspended in silicone oil can be manipulated with the velocity of 40-50 mu m/s. The driving force up to 160 pico-Newtons could be generated for manipulating a gas bubble of 300 picoliters. (C) 2011 American Institute of Physics. [doi:10.1063/1.3580760]