1. Key Laboratory of Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing, People’s Republic of China
2. Tsinghua University-University of Waterloo Joint Research Center for Micro/Nano Energy & Environment Technology, Tsinghua University, Beijing, People’s Republic of China
3. Department of Mechanical & Mechatronics Engineering, University of Waterloo, Ontario, Canada