1. Thermal Management Research Group, Efficient Energy Transfer (ηET) Department, Bell Laboratories Ireland, Alcatel-Lucent Ireland Ltd., Blanchardstown Business & Technology Park, Snugborough Road. Dublin 15, Ireland
2. Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
3. Stokes Institute, University of Limerick, Limerick Ireland
4. Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
5. Mathematics Institute, University of Warwick, Coventry CV4 7AL, United Kingdom
6. Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States