Browsing by Author "Fan, SK"

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<bold>DIRECT HANDWRITING MANIPULATION OF DROPLETS BY SELF-ALIGNED MIRROR-EWOD ACROSS A DIELECTRIC SHEET</bold>
(2006)
Chuang, KC
;
Fan, SK
;
材料科學與工程學系奈米科技碩博班
;
Graduate Program of Nanotechnology , Department of Materials Science and Engineering
In this paper, we demonstrate a novel approach to generate electrowetting on a dielectric sheet over a liquid electrode. A 12.5 pm-thick PVDC film (Saran wrap) was used as the dielectric sheet. Two important phenomena were found: (1) EWOD not only occurs on the manipulated droplet, but also the liquid electrode (mirror-EWOD), (2) the mirror-EWOD causes the manipulated droplet and the liquid electrode self-aligned when they are in comparable sizes. Based on these discoveries, a direct handwriting droplet manipulation platform was designed and fabricated, in which droplets can be transported by a droplet-tipped stylus across a dielectric sheet. PVDC film was also applied in conventional EWOD devices as a disposable dielectric layer.
Differential response of vacuolar proton pumps to osmotica
(2006)
Chiu, FS
;
Hsu, SH
;
Chen, JH
;
Hsiao, YY
;
Pan, YJ
The vacuole is a fundamental and dominant organelle and occupies a large part of the total cell volume in most mature plant cells. The higher-plant vacuole contains two types of proton-translocating pumps, H+-ATPase (EC 3.6.1.3) and H+-pyrophosphatase (EC 3.6.1.1), residing on the same membrane. These two enzymes generate roughly equal proton gradients across the vacuolar membrane for the secondary transport of ions and metabolites. However, the pumps respond differentially to stress in order to maintain critical functions of the vacuole. In this work, tonoplasts from etiolated mung bean seedlings ( Vigna radiata L.) were used to investigate the function of these two enzymes under high osmotic pressure. At high concentrations of sucrose or sorbitol, the light scattering and volume of isolated vesicles were progressively changed. Concomitantly, enzymatic activities, proton translocation, and coupling efficiencies of these two proton-pumping enzymes were inhibited to various extents under high osmotic pressure. No significant change in enzymatic activities of purified vacuolar H+-PPase and H+-ATPase under similar conditions was observed. We thus believe that the membrane structure is an important determinant for proper function of proton pumping systems of plant vacuoles. Furthermore, kinetic analysis shows different variation in apparent V-max but not in K-M values of vacuolar H+-PPase and H+-ATPase at high osmolarity of sucrose and sorbitol, respectively, suggesting probable alterations in substrate hydrolysis reactions but not substrate-binding affinity of the enzymes. A working model is proposed to interpret supplemental roles of vacuolar H+-PPase and H+-ATPase to maintain appropriate functions of plant tonoplasts.
Direct handwriting manipulation of droplets by self-aligned mirror-EWOD across a dielectric sheet
(2006)
Chuang, KC
;
Fan, SK
;
材料科學與工程學系奈米科技碩博班
;
Graduate Program of Nanotechnology , Department of Materials Science and Engineering
In this paper, we demonstrate a novel approach to generate electrowetting on a dielectric sheet over a liquid electrode. A 12.5 pm-thick PVDC film (Saran wrap) was used as the dielectric sheet. Two important phenomena were found: (1) EWOD not only occurs on the manipulated droplet, but also the liquid electrode (mirror-EWOD), (2) the mirror-EWOD causes the manipulated droplet and the liquid electrode self-aligned when they are in comparable sizes. Based on these discoveries, a direct handwriting droplet manipulation platform was designed and fabricated, in which droplets can be transported by a droplet-tipped stylus across a dielectric sheet. PVDC film was also applied in conventional EWOD devices as a disposable dielectric layer.
Droplets oscillation and continuous pumping by asymmetric electrowetting
(2006)
Wang, TT
;
Huang, PW
;
Fan, SK
;
材料科學與工程學系奈米科技碩博班
;
Graduate Program of Nanotechnology , Department of Materials Science and Engineering
This paper reports a new approach to digital microfluidic systems based on asymmetric electrowetting-on-dielectric (AEWOD) mechanism. On the AEWOD device, droplets can be oscillated or continuously pumped on an open surface by none or limited control electric circuits. This paper presents: (1) the AEWOD phenomenon, (2) droplet oscillation controlled by AEWOD force, and (3) the demonstration of unidirectional and bidirectional droplet pumping on AEWOD device.
Numerical confirmation of inelastic trap-assisted tunneling (ITAT) as SILC mechanism
(2001-10-01)
Kang, TK
;
Chen, MJ
;
Liu, CH
;
Chang, YJ
;
Fan, SK
This paper presents a quite comprehensive procedure covering both the stress-induced leakage current (SILC) and oxide breakdown, achieved by balancing systematically the modeling and experimental works. The underlying model as quoted in the literature features three key parameters: the tunneling relaxation time tau, the neutral electron trap density N-t, and the trap energy level E-t. First of all, 7-nm thick oxide MOS devices with wide range oxide areas are thoroughly characterized in terms of the optically induced trap filling, the charge-to-breakdown statistics, the gate voltage developments with the time, and the SILC I-V. The former three are involved together with a percolation oxide breakdown model to build N-t explicitly as function of the stress electron fluence. Then the overall tunneling probability is calculated, with which a best fitting to SILC I-V furnishes tau of 4.0 x 10(-13) s and E-t of 3.4 eV. The extracted tau is found to match exactly that extrapolated from existing data. Such striking consistencies thereby provide evidence that inelastic trap-assisted tunneling (ITAT) is indeed the SILC mechanism. Differences and similarities of the involved physical parameters between different studies are compared as well.