Category: Micro- and Nanotechnologies
A high variety of microfluidic platforms that aim to miniaturize and automate biochemical assays have been developed in the last two decades but for the majority of these there is no progression beyond the proof-of-concept experiments due to the complexity of fabricating and operating them. We introduce a novel method for creating arrays of fluidic-walled sessile droplets, the equivalent of conventional microtiter plates, using only standard dishes and fluids. The method consists in displacing a continuous fluid layer into a pattern of isolated chambers overlaid with an immiscible liquid to prevent evaporation. This liquid plays an additional role acting as a physical barrier, making the system contamination resilient. The resulting chambers have a rectangular footprint and use the maximum surface available. Pliant, self-healing fluid walls confine volumes as small as 10 nl. The technique is not restricted to arrays but allows for quick and flexible prototyping of a high range of microfluidic circuits with irregular patterns.
A basic set of capabilities is demonstrated by accommodating cell and organism-based assays: biocompatibility, ways of introducing samples and reagents in the system, and methods that allow the retrieval of samples for subsequent analysis. The scalability of the system facilitates assays at both population and single-specimen level. Time-efficient means of manipulating fluids have been implemented to accommodate high-throughput experiments. Fluidic-walled chambers offer good optical clarity making them ideal for imaging the samples contained within. The simplicity of the technique eliminates the need for expensive machinery or equipment. It is all incorporated in a benchtop system that can produce and access arrays of hundreds of fluidic chambers within minutes.
Cristian Soitu– DPhil student, University of Oxford, Oxford, England, United Kingdom