title: Droplet sensing by measuring the capacitance between coplanar electrodes in a digital microfluidic system.
abstract: In this paper, we report a novel method of droplet sensing in a two-plate digital microfluidic system (DMS) based on coplanar capacitance measurement. The total capacitance between the two adjacent electrodes on the lower plate depends on the position of the droplet. Both numerical and experimental results show that the capacitance is maximal at the midpoint between two electrodes. The value of maximum capacitance increases with the volume of the droplet. Further, the measured capacitance is a function of the gaps between the electrodes as well as the plates. This new method of droplet sensing adds to the functionality of DMSs by allowing single plate measurement.
authors.affiliation: Okanagan School of Engineering, University of British Columbia Kelowna, BC V1V 1V7, Canada. biddut.bhattacharjee@ubc.ca
authors.forename: Biddut
authors.initials: B
authors.lastname: Bhattacharjee
authors.forename: Homayoun
authors.initials: H
authors.lastname: Najjaran
mesh_terms: D004566:Electrodes; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D010316:Particle Size