Thermal Exchange of Glass Micro-Fibers Measured by the 3ω Technique

Tuyen Duc D Nguyen (1, 2) , Jacques Richard (1) , J. Doumouro (3) , Y. de Wilde (4) , Olivier Bourgeois (1)

1 NEEL - TPS - Thermodynamique et biophysique des petits systèmes
2 MSME - Laboratoire de Modélisation et Simulation Multi Echelle
3 ILL - Institut Laue-Langevin
4 IL - Institut Langevin - Ondes et Images (UMR7587)

In this work, we propose an experimental setup to measure the thermal conductivity and specific heat of a single suspended glass fiber, as well as the thermal contact resistance between two glass fibers. By using optical lithography, wet and dry etching and thin film deposition, we prepared suspended glass fibers that are coated by niobium nitride thin film (NbN) used as room temperature thermal transducer. By using the 3ω technique, the thermal conductivity of glass fiber was measured to be 1.1 W.m −1 .K −1 and specific heat 0.79 J.g −1 .K −1 around 300 K under vacuum conditions. By introducing exchange gas into the measurement chamber, influence of the gas on the heat transfer was studied, and the convection coefficient h for all the measurement ranges from a pressure of 0.01 hPa to 1000 hPa, over more than five orders of magnitude, has been obtained. By adding a bridging glass fiber on top of two other suspended glass fibers, it was possible to estimate the thermal contact resistance between two glass fibers R c in the range of 10 7 K.W −1 to 10 8 K.W −1 .

Domaines: Micro et nanotechnologies/Microélectronique; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Tuyen Duc D Nguyen, Jacques Richard, J. Doumouro, Y. de Wilde, Olivier Bourgeois. Thermal Exchange of Glass Micro-Fibers Measured by the 3ω Technique. Journal of Heat Transfer, 2020, 142 (10), pp.101701. ⟨10.1115/1.4047501⟩. ⟨hal-03042470⟩