Rapid, selective, and uniform heating of sub-microliter size fluid volumes is vital for micro total analysis system (?gTAS) applications. In this work, we present an approach to localized and selective heating of fluids in a microfluidic network. This is accomplished with microwave dielectric heating by using a coplanar waveguide (CPW) transmission line to deliver heat to a specific region in a microchannel. An elastomeric microchannel was positioned over the CPW fabricated by photolithography on a glass substrate. S-parameter and temperature measurements were used with theoretical analysis to fully characterize the temperature rise of the fluid by microwave power absorption, and it is shown that the temperature rise of the fluid is predominantly due to microwave heating. We observed a 0.95 ?aC/mW temperature rise at 15 GHz. Our theoretical analysis confirms that classical microwave absorption theory is valid at this scale.
Citation: Journal of Micromechanics and Microengineering
Pub Type: Journals