Authors: M. Abolhasani, K.D. Devlin, H. Najjaran, M. Hoorfar, J.F. Holzman
Affilation: The University of British Columbia Okanagan, Canada
Pages: 460 - 463
Keywords: multiplexer, digital microfluidic, cross-referencing, bi-polar voltage activation, threshold voltage
This paper reports a novel system-level design for digital microfluidic (DMF) devices. A DMF multiplexer structure based on a cross-referencing architecture is presented. The design makes use of bi-polar voltage activation and threshold effects to overcome addressability limitations and eliminate inter-droplet interference. The conventional cross-referencing system relies on two sets of rectangular electrodes: top rows and bottom columns. The droplet can move between the overlying top electrode plate and underlying bottom electrode plate. Such a system achieves M×N addressability with only M+N electrodes. There remains one major drawback to the above cross-referencing method. If, for example, one of the row electrodes is activated with a high-voltage to induce motion in a microdroplet adjacent to the grounded electrode, the potential for motion will exist for any microdroplets intersecting the activated row electrode. Simultaneous motion is typically undesirable as complete isolation, and addressability in the two-dimensional plane with systems incorporating numerous microdroplets is no longer possible. The proposed DMF multiplexer described in this paper can allow for complete M×N addressability in a cross-referencing architecture through the simultaneous use of threshold-based voltage actuation and bipolar voltage activation on the overlying and underlying electrodes.