Dissolvable-Film Enabled Flow Control for Lab on a Disc

The “lab-on-a-disc” (LoaD) platform has become of increasing interest to the microfluidics community due to its suitability for point-of-use / point-of-care deployment where ruggedness, portability, rapid turn-around times and ease-of-use are key. This platform uses microfluidic cartridges which are typically the same size as optical discs (CDs or DVDs) and which are rotated about their axis to create a centrifugal force. Like other lab-on-a-chip platforms the centrifugal platform offers advantages towards assay automation, small sample and reagent usage, and small instrument footprints. However, unlike most pressurised Lab-on-a-Chip systems the LoaD operates at atmospheric pressure and can be loaded using a simple pipette. This, along with the disposability of the discs and inherent capability to centrifuge blood, makes them particularly suitable for human diagnostics and low-resource settings.
Flow control techniques such as valves are key for the LoaD as the centrifugal force acts on all liquids on the disc. Recently, Ducrée labs have developed new valving technologies based on water dissolvable films. These valves include burst valves and a new ‘event-triggered’ valving paradigm which function in a manner similar to an electrical relay. This talk will provide an overview of the valving technologies developed within Ducrée Labs and describe how these valves can be configured, using Boolean-like network relationships, to implement the steps required for bioassays. In particular this talk will describe the presenter’s work towards developing a mechanism for buoyance-driven centripetal pumping using DFs and a dense non-aqueous fluorocarbon liquid. Centripetal pumping is critical for the LoaD platform as it increases the number of sequential operations which can be performed on a disc. It also permits reagent storage on the periphery of the disc rather the centre where disc real-estate is most valuable.