Electronic cooling of a submicron-sized metallic beam
  We demonstrate electronic cooling of a suspended AuPd island using superconductor-insulator-normal metal tunnel junctions. This was achieved by developing a simple fabrication method for reliably releasing narrow submicron sized metal beams. The process is based on reactive ion etching and uses a conducting substrate to avoid charge-up damage and is compatible with e.g. conventional e-beam lithography, shadow-angle metal deposition and oxide tunnel junctions. The devices function well and exhibit clear cooling; up to factor of two at sub-kelvin temperatures. 
J.T. Muhonen, A.O. Niskanen, M. Meschke, Yu.A. Pashkin, J.S. Tsai, L.   Sainiemi, S. Franssila and J.P. Pekola