Volume 24 Issue 11 - Publication Date: 1 November 2005
Coordinating Multiple Droplets in Planar Array Digital Microfluidic Systems
E. J. Griffith and S. Akella Department of Computer Science, Rensselaer Polytechnic Institute, Troy, NewYork 12180, USA
In this paper we present an approach to coordinate the motions of droplets in digital microfluidic systems, a new class of lab-on-a-chip systems for biochemical analysis. A digital microfluidic system typically consists of a planar array of cells with electrodes that control the droplets. The primary challenge in using droplet-based systems is that they require the simultaneous coordination of a potentially large number of droplets on the array as the droplets move, mix, and split. In this paper we describe a general-purpose system that uses simple algorithms and yet is versatile. First, we present a semi-automated approach to generate the array layout in terms of components. Next, we discuss simple algorithms to select destination components for the droplets and a decentralized scheme for components to route the droplets on the array. These are then combined into a reconfigurable system that has been simulated in software to perform analyses such as the DNA polymerase chain reaction. The algorithms have been able to successfully coordinate hundreds of droplets simultaneously and perform one or more chemical analyses in parallel. Because it is challenging to analytically characterize the behavior of such systems, simulation methods to detect potential system instability are proposed.
Multimedia Key
= Video = Data = Code = Image
Example 1: PCR analysis, in batch mode. Waste droplets are depicted as
blue diamonds. (27.4 MB)
Example 2: PCR analysis, in continuous mode. (32.8 MB)
Example 3: Two analyses running in parallel (continuous mode). Droplets of the PCR analysis are depicted as squares and droplets of the second analysis are depicted as diamonds. (32.7 MB)
Example 4: Unstable PCR example (continuous mode), showing the
system reaching a deadlock state. (53.2 MB)
Return to Contents