A Low-Voltage Droplet Manipulation via Tunable Wetting on a Polypyrrole (DBS) Surface

W. Xu, Y. Tian, H. Bisaria, P. Ahn, X. Li, Y.-T. Tsai, C.-H. Choi, E.-H. Yang
Stevens Institute of Technology, US

Keywords: droplet manipulation, tunable wetting, polypyrrole

Summary:

Electrowetting on dielectric (EWOD) technique has been used to manipulate microliter-sized individual droplets for microfluidic application. However, EWOD-based techniques typically require relatively high actuation voltages (12-80V), which is undesirable for biomedical applications or the applications including on-site operation. Therefore, an alternative technique to realize a low-voltage droplet manipulation would be extremely beneficial. In this work, we demonstrate a new mechanism of the liquid droplet manipulation at low voltages (< 1.5 V) by utilizing the tunable wetting on dodecylbenzenesulfonate doped polypyrrole (PPy(DBS)) surface. In a slightly tilted (4°) microchannel, we further demonstrate a controlled lateral transport of an aqueous droplet via tunable wetting on PPy(DBS). The reported mechanism will pave a new way for the development of future low-voltage digital microfluidics platform.