(155g) Harnessing Eddy Current Induced Microfluidic Heating to Actuate Sample Preparation and Nucleic Acid Amplification Reactions in Lab-on-a-Disc Platforms.

Existing portable molecular diagnostic systems face significant limitations due to their dependence on bulky and power-intensive Peltier heating elements, creating a barrier for point-of-care applications. We present a novel method to overcome this obstacle by leveraging the established framework of centrifugal microfluidics. The study focuses on harnessing eddy currents generated by the relative motion between a spinning conductor (disc) and stationary magnets, which create localized "hot spots" on the spinning disc. Our preliminary experiments demonstrate that eddy current-induced thermal dissipation resulting from the relative velocity between the metal in the spinning disc and stationary magnets can heat assay samples to relevant temperatures. Moreover, parameters such as rotational speed, magnetic strength, conductor type, and geometric parameters can be altered to precisely control the fluid temperature in contact with the metal. The initial setup includes a brushless DC motor, a Poly(methyl methacrylate) (PMMA) disc housing copper pieces, and a fluid sample surrounded by stationary neodymium magnets. We demonstrate the ability to modulate temperature profiles and ramp rates by adjusting the disc's angular velocity. This framework has the potential to usher in a new generation of molecular diagnostic platforms that integrate both sample preparation and thermal cycling modules in a single platform while concurrently reducing device complexity and cost associated with molecular diagnostics in a variety of settings.