Abstract

Centrifugal microfluidic systems bear great potential for applications where ruggedness, portability, ease-of-use, and cost efficiency are critical. However, due to the unidirectional nature of the centrifugal pumping force, the number of sequential process steps which can be integrated on these “Lab-on-a-Disc” (LoaD) devices is limited by their finite radial extension. To significantly widen this bottleneck and thus expand the scope of applications that can be ported on these LoaD platforms, various groups have developed a range of centripetal pumping mechanisms. Here, we present two advancements over our previous efforts in this area by combining buoyancy-based pumping with dissolvable film (DF) valves. First, we present a buoyancy-driven, reciprocating flow of a dense liquid initially located an upper reservoir and a sample in a peripheral reservoir. Secondly, we combine buoyancy-driven centripetal pumping with sample discretization and metering to fully integrate and automate a liquid handling protocol towards implementing a multi-parameter bioassay on a disc.