An EWOD-based micro diluter with high flexibility on dilution ratio

• Published in: Microsystem technologies : sensors, actuators, systems integration Vol. 23; no. 8; pp. 3645 - 3651
• Main Authors: Wang, Ying-Bin, Huang, Jun-Hao, Lee, Meng-Shiue, Huang, Cheng-Yeh, Huang, Cheng-Sheng, Yamashita, Ichiro, Tu, Yung-Yi, Hsu, Wensyang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2017
• Subjects: Electronics and Microelectronics; Engineering; Instrumentation; Mechanical Engineering; Nanotechnology; Technical Paper; Droplet Size; Driving Voltage; High Flexibility; Dilution Ratio; Electrode Size
• ISSN: 0946-7076; 1432-1858
• DOI: 10.1007/s00542-016-3146-2

Dilution is a common procedure in biological and chemical analyses to perform tests at different concentrations. In previously reported micro diluters, although they could provide a wide dilution range, only limited dilution ratios were demonstrated, i.e. low flexibility in dilution ratio. Here, a droplet-based micro diluter with high flexibility on dilution ratio is proposed, fabricated, and tested. Through combination of five different electrode sizes using electrowetting-on-dielectric (EWOD) technique, the proposed micro diluter can provide 49 dilution ratios at dilution range from 1/2 to 1/50. Experimental results verify that different dilution ratios can be successfully generated, even at the most difficult low concentration range. Comparing to the design with equal electrode size in conventional EWOD-based microfluidic chip, the proposed design with unequal electrode sizes can reduce the operation steps to achieve high flexibility on dilution ratios efficiently.