Laboratory for Integrated

Micro-Mechatronic Systems


Thermionic cooling and needles patch biosensors. April 2019, in Tokyo.


The employer

LIMMS (Laboratory for Integrated Micro Mechatronic Systems) is an international laboratory between the French CNRS (Centre National de la Recherche Scientifique) and Institute of Industrial Science (IIS), the University of Tokyo, located in Komaba, Tokyo. LIMMS has more than 20 years of experience in international cooperative research and has welcomed more than 200 researchers from France and Europe.

LIMMS opens a new postdoctoral position in the laboratory of Professor Kazuhiko HIRAKAWA.Description of the Host Professor’s laboratory (and team):
Kazuhiko Hirakawa,
CIRMM, Institute of Industrial Science, The University of Tokyo

The mission

The principal investigator and his colleagues at Institute of Industrial Science (IIS), University of Tokyo, are working on novel solid-state cooling devices based on the semiconductor quantum heterostructures. In the modern electronics, energy-saving and thermal-management technologies are becoming extremely important. Indeed, electrical fields applied in nano-electronics generate a strong self-heating leading to a significant reduction in the lifetime of devices. On the other hand, the refrigeration of such nano-devices is extremely power consuming. By directly targeting the hot spots of the chips, local coolers can provide the key to an efficient in situ heat management. We are interested in realizing novel solid-state cooling devices based on the concept of “thermionic/evaporative cooling” that can efficiently refrigerates both electron and lattice.  In “thermionic/evaporative cooling”, we use resonant tunneling and subsequent thermionic emission to remove energy from the quantum well layer. We have recently demonstrated that such a structure can provide a remarkable electron cooling by as much as 50 K. The aim of this project is to further improve electron cooling and to demonstrate the lattice refrigeration as well. 

The project consists of (1) the fabrication of solid-state refrigeration devices using GaAs-based heterostructures and (2) the development of new temperature sensing method using photoluminescence and micro-electromechanical systems (MEMS) structures. By doing so, we will demonstrate an original approach for solid-state refrigeration based on quantum heterostructures to provide efficient local cooling. The prospective postdoctoral researcher is expected to join and pursue this project.

The laboratory is well equipped with nanofabrication apparatus and measurement setups. Furthermore, a long-term CNRS visiting scientist in the group will perform quantum transport calculations and support the project from the theory side. The project will be conducted in collaboration with the semiconductor research groups at IIS and another CNRS lab. (Next-PV), University of Tokyo.

Period of Postdoctoral Position: Two years staring after April. 1, 2019

Rewards: Paid equivalent to the JSPS Postdoctoral position

Geographic mobility: international


Candidates are expected to have a background of solid state physics and/or device physics, and have interests in nanotechnologies/nanosciences. Skills on microfabrication and small signal measurements will be helpful. A challenging spirit would help a lot for tackling into this interdisciplinary and cutting-edge research area.


solid-state refrigeration, thermionic cooling, evaporative cooling, quantum structures, micro-electromechanical systems (MEMS), thermal management

Post doctoral on electronic
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