BNR #50 - Dr. Sebastian Volz (LEM2C, UPR-CNRS 288, France), July 30th 2013, PM5:00- C-lounge

Dr. Sebastian Volz, 

Laboratoire d'Energétique Moléculaire et Macroscopique, Combustion, UPR CNRS 288, Ecole Centrale Paris - 92295 Châtenay Malabry - France.

Nanostructure based Design of Materials Properties for the Thermal Management of Micro and Nanosystems  

The thermal management of today's micro and nanodevices is mainly based on two strategies. 

The first one is passive and consists in reducing the bottlenecks on the heat path by introducing Thermal Interface Materials (TIMs) at all scales -from the transistor device to the package-. Those TIMs have to be either very viscous and liquid-like to fill gaps in the package, or solid and nanosized to be introduced near to the active component. In either cases, they have to ensure efficient heat transport and therefore involve either percolating micro-nanostructures in a polymer or single nano-objects such as graphene sheets or carbon nanotubes.

The second strategy targets an active temperature control with microthermoelectric coolers. Thermoelectric conversion is a less known way of producing coldness due to its poor conversion efficiency. It is however the sole solution that at once allows heating -and- cooling with a solid microdevice. Recent progresses in thermoelectricity have been emerging because of the strong heat conduction reduction due to nanostructuration. The introduction of interfaces and surfaces in nanosized sub-components indeed produces the effective scattering of heat carriers, which are the sound particles or the phonons in dielectrics. 

The seminar will introduce the technological challenges and then the main approaches to phonon transport in nanostructures. A set of studies concerning unconventional heat conduction in nanoscale objects will then be proposed.  Investigation of phonon scattering at perfect interfaces as for instance in layered systems or in nano-object composites will then be developed. We will propose a new approach to the estimation of the interfacial contact resistance based on atomic scale simulations, which have been applied in several configurations such as carbon based thermal interface materials.


Dr. Sebastian Volz

Directeur de Recherche au Centre National de la Recherche Scientifique, Equipe Transferts aux courtes échelles dans les milieux denses. 

Directeur du GDR CNRS européen "Thermal NanoSciences and NanoEngineering", 

Laboratoire d'Energétique Moléculaire et Macroscopique, Combustion, UPR CNRS 288, Ecole Centrale Paris - 92295 Châtenay Malabry - France

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