Current global energy demand is expected to double within the next 20 years as energy consumption rate grows rapidly in developing countries such as China and India . In addition to the possibility of a‘peak oil’situation , there are concerns about excessive usage of other fossil fuels such as natural gas and coal as their effects on global warming and food/water supply become widespread. Undoubtedly, it is time to shift our paradigm of obtaining and consuming energy from the traditional way to a more sustainable one. We perform research on thermoelectric energy conversion, which can be a cost-effective way of not only increasing energy conversion efficiency by recycling waste heat but also generating electricity from solar energy in a solar thermal photovoltaic module . The SEM image on the side shows a device for measuring a power factor of an individual nanowire from which high thermoelectric efficiency can be expected by the quantum confinement effect as well as the reduction of thermal conductivity.
 Smalley, R.E., Future Global Energy Prosperity: The Terawatt Challenge. MRS Bulletin, 2005. 30(06): p. 412-417
 Ugo, B., Peak oil: The four stages of a new idea. Energy, 2009. 34(3): p. 323-326.
 Baxter, J., et al., Nanoscale design to enable the revolution in renewable energy. Energy & Environmental Science, 2009. 2(6): p. 559-588.
-Thermal management in electronics
As for modern electronics, the fast miniaturization in size and the acceleration in processing speed have resulted in extremely high power density. Moreover, the insufficient ability to dissipate the heat is the primary cause for degradation of failure of electronics . Accounting for these challenges, we aim to develop new solutions for thermal management at the intersection of thermal transport and nanotechnology. As a typical example of the efforts, the SEM image on the side shows a scanning electron micrograph of a suspended micro device for measuring the thermal conductivity of supported graphene which was published in Science in 2010 . Due to its ultrahigh thermal conductivity, graphene is thought to be used as a novel thermal spreader in future nanoelectronics.
 Majumdar, A., Thermoelectric devices: Helping chips to keep their cool. Nat Nano, 2009. 4(4): p. 214-215.
 Seol et al., Two Dimensional Phonon Transport in Supported Graphene, Science, 2010 (328), 213-216
-Nano-sensors & actuators
Our group has a specialty of measuring thermal properties of various nanomaterials with an extreme accuracy of ~nW/K. In addition to this measurement technique, it is generally needed to fabricate measurement devices for thermal measurements as shown on the side. These techniques can be easily modified and applied to developing micro/nanoscale sensors and actuators called MEMS/NEMS devices.