Abstract

Self-Coalescing Flows: A Powerful Method For Integrating Biochemical Reactions In Portable Diagnostic Devices

Emmanuel Delamarche, Manager, Precision Diagnostics, IBM Research GmbH

Diagnostics are ubiquitous in healthcare because they support prevention, monitoring, and treatment of diseases. Specifically, point-of-care diagnostics (POCDs) are particularly attractive for identifying diseases near patients, quickly, and in many settings and scenarios. POCDs can also trace exposure and acquired immunity of populations exposed to infectious diseases and screen metabolic deficiencies of individuals, who may be exposed to severe drug side effects. However, a long-standing challenge with POCDs is the need to integrate reagents in closed devices for a large number of potential applications. Following our previous contributions on developing capillary-driven microfluidic chips for highly miniaturized immunoassays, controlling and monitoring flow with nanoliter precision, and securing diagnostics against counterfeiting with dynamic optical security codes, we recently demonstrated how to shape and fold liquids inside microfluidic chambers to dissolve reagents with extreme precision. In this presentation, I will explain the underlying concept of this method, called self-coalescing flows, and will illustrate how it can be used to perform various assays, ranging from enzymatic assays, to immunoassays and molecular assays. Despite self-coalescing flows being still an open research topic in fluid physics, their implementation is surprisingly facile and robust and therefore may benefit the entire community working on POCDs.