Sauvage's scientific work has focused on creating molecules that mimic the functions of machines by changing their conformation in response to an external signal. His Nobel Prize work was done in 1983, when he was the first to synthesize a catenane, a complex of two interlocking ring-shaped molecules, which were bonded mechanically rather than chemically. Because these two rings can move relative to each other, the Nobel Prize cited this as a vital initial effort towards making molecular machine. The other two recipients of the prize followed up by later creating a rotaxane and a molecular rotor