Diverse thermal transport phenomena at small length and time scales, and at low temperatures. He has recently investigated the physics of heat flow at atomistic levels to improve the reliability of nanoelectronics and to engineer materials with novel thermophysical properties. His research will greatly enhance energy efficiency and power delivery at the microscale, and facilitate greater innovation in the microarchitecture of computers. He recently co-invented a method for making substrates with thermally conductive structures, as well as the resulting embedded carbon nanotube heat-spreader substrate.