Fast Online Synthesis of Digital Microfluidic Biochips

Abstract

Abstract-We introduce an online synthesis flow, focusing primarily on the virtual topology and operation binder, for digital microfluidic biochips, which will enable real-time response to errors and control flow. The objective of this flow is to facilitate fast assay synthesis while minimally compromising the quality of results. In particular, we show that a virtual topology, which constrains the allowable locations of assay operations such as mixing, dilution, sensing, etc., in lieu of traditional placement, can significantly speed up the synthesis process without significantly lengthening assay execution time. We present a base virtual topology and show how it can be leveraged to reduce algorithmic runtimes and guarantee rout ability. We later present several variations of the virtual topology and present experimental results demonstrating best-design practices. We present two binding solutions. The first is a left-edge binding algorithm, while the second is a more intelligent path-based binding algorithm that leverages spatial and temporal locality to produce superior results.

A Low-Cost Field-Programmable Pin-Constrained Digital Microfluidic Biochip

“…The router produces a list of electrodes to activate during each droplet actuation cycle, i.e., the time it takes to move a droplet from one electrode to the next. While computing droplet routes, the router must ensure that droplets do not interfere with one another while traversing the DMFB array [12], [13], [34]; to prevent droplets from accidental collisions, the router creates an interference region around a stationary droplet at the beginning of a droplet actuation cycle, as seen in Fig. 4(a).…”

“…The FPPC-DMFB is a pin-constrained virtual topology [10], [12], [13], which segregates the DMFB surface area into modules that perform assay operations (mixing, splitting, storage, detection, etc.) and a network of streets that transport droplets between modules and I/O reservoirs.…”

“…In a direct-addressing chip, virtual topologies limit the flexibility and reconfigurability of the device in order to facilitate fast online synthesis algorithms, which can respond to sensory feedback provided by the device in real-time [12], [13]. Pin-constrained DMFBs exhibit limited flexibility and reconfigurability; imposing a virtual topology to achieve general-purpose operation is a favorable innovation [11].…”

“…The FPPC-DMFB contains a vertical column of mixing modules on the left (blue/orange electrodes, Pins [10][11][12][13][14][15][16][17][18][19][20] and a vertical column of modules on the right (orange electrodes, Pins 31-36) that perform splitting, storage, and detection (which requires an external detector affixed above the module); we call these modules SSD modules.…”

“…Similar to prior work by Grissom and Brisk [13], the concurrent router compacts the sequential routing solution (in time) so that multiple droplets can route in parallel without inadvertently colliding. Their algorithm compacts droplet routes one-at-a-time, delaying the starting time of each route routes until a legal solution is obtained.…”