CC BY
2Multifunctional superhydrophobic platform for control of water microdroplets by non-uniform electrostatic field
G. Pavliuk1*, A. Zhizhchenko2, O. Vitrik2
1-Far Eastern Federal University, Ajax Bay, 10, Russky Island, Vladivostok, Russia, 690922 2- Institute of Automation and Control Processes (IACP) FEB RAS, Vladivostok, Russia, 690041
* georgii. [email protected]
Platforms for manipulating liquid microdroplets (PMD) are required in microfluidic systems [1,2] in particular in laboratories on a chip, as well as advanced sensors and other devices [3,4]. The implementation of a sequence of controlled biochemical, biological and analytical reactions on such platforms is achieved by controlled selective movement and coalescence of droplets or their groups on the working surface of PMD. In this work, we report a new approach to the control of liquid microdroplets based on non-uniform electrostatic fields. This field, created near the selected droplet, leads to its polarization. That is, the droplet acquires a pronounced dipole moment. Since the field is non-uniform, the polarized droplet begins to accelerate in the direction of the field gradient (Fig. 1a). To increase the mobility of the droplet, the latter is placed on a superhydrophobic surface (Fig. 1b).
Fig. 1. (a) Schematic of the platform for micromanipulation of liquid droplets and its mechanism of action. (b) SEM image of the topography of a superhydrophobic surface.
The developed PMD has demonstrated the ability to move droplets along predefined trajectories in the volume range from 0.2 ^L to 200 ^L. In the most demanded from a practical point of view range of volumes 3 ^ 15 ^L, the speed of movement is 17 ^ 75 mm/s. The developed platform also provides the possibility of controlled coalescence of droplets, controlled chemical reactions for their contents, including analytical ones. We believe that the presented liquid droplet micromanipulation platform has great potential in chemical and biological analysis and can become a useful tool for various microfluidics applications.
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