Scientists in China have made a molecular spring that mimics stretchable systems in living systems, for example titin (a protein found in cardiac and skeletal muscles).
Although molecular springs based on rotaxane are known, they can only change their length stepwise. This new rotaxane-based spring changes its length continuously as solvent polarity varies and so is a better mimic of biological springs.
Link to journal article
A solvent-driven molecular spring
Z Zhang et al
Chem. Sci., 2012, DOI: 10.1039/c2sc20728a
