Real-time thermal characterization of 12 nl fluid samples in a microchannel

This work presents a novel method and a device for real-time simultaneous measurement of the thermal conductivity and heat capacity of 12 nl fluid samples. The device uses a micromachined thermal sensor composed of a microchannel and a thin-film probe. The method, based on the 3 omega technique, employs a multiparameter-fitting scheme to determine the thermal properties with numerical computation of heat transfer. The thermal properties of 12 nl samples have been measured successfully by the sensor. Furthermore, real-time thermal characterization of fluid samples flowing in a microchannel has been demonstrated, manifesting strong potential of the proposed technique as an in situ probe in various microfluidic applications. (c) 2008 American Institute of Physics.