Study of Two-Dimensional Open EWOD System using Printed Circuit Board Technology
Digital microfluidics (DMF) emerged as a popular technology for lab on chip (LOC) application, which allows full and independent control over droplets on an array of electrodes. In this work, open electrowetting on dielectric technique (EWOD) based on printed circuit board has been investigated, which has a wide range of applications. The most of the traditional EWOD chips array of electrode pads typically in 1-D (one-dimensional) line pattern designed for specific operation at a time, limit the utilization of estate. In the proposed system, 2-D (two-dimensional) array of 22 electrodes, controlled by 8 control signals designed and fabricated to enhance reconfigurable paths. Bio-compatible polydimethylsiloxane (PDMS) is used as a dielectric as well as a hydrophobic layer. The controlled droplet transport and mixing are successfully done on the fabricated device. The effect of ground wire configuration on droplet velocity is investigated and results are verified with estimated droplet velocity. The maximum velocity points are correlated with maximum electric field obtained by electromagnetic simulations for all ground wire configurations. The detection of milk adulteration is successfully demonstrated using open EWOD device. This work illustrates the promise of open two-dimensional EWOD device for digital microfluidics applications.
