Electrokinetic Manipulation of Microdroplets and Microparticles across a Dielectric Thin Film
|關鍵字:||電動力操控;實驗室晶片;介電濕潤;鏡像介電濕潤;介電泳;絕緣介電泳;Electrokinetic manipulation;Lab-on-a-Chip;Electrowetting-on-dielectric (EWOD);Mirror-EWOD;Dielectrophoresis (DEP);Insulator-based dielectrophoresis (iDEP)|
In this thesis, we demonstrate a novel approach to generate electrowetting on a dielectric sheet over a liquid electrode. A 12.5 micrometer-thick PVDC film 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. We also miniaturize this system to a battery powered mirror-EWOD portable device successfully. Another topic is that a particle separator was demonstrated based on 3-D iDEP (insulator-based dielectrophoresis). In this chip, we separate beads in 5-µm diameter and 1-µm diameter successfully. It was observed that the 5-µm beads were repelled from the microholes by nDEP and the 1-µm beads were trapped into microholes by pDEP. Finally, we hope to integrate mirror-EWOD and 3-D iDEP in one chip to achieve the concept of Lab-on-a-chip.