a DNA muscle

There are lots of different nanomachines built from DNA these days, but I really liked this example from Angewandte where Lubrich et al. used the "DNA fuel" approach to create a long contractile fibre, much like a muscle fibre. Add one kind of DNA strand, and it contracts, add the complementary strand and it detaches the first strand allowing the fibre to return to the start (and the waste double strand can presumably be separated and recycled as well).

A Contractile DNA Machine
Daniel Lubrich, Jie Lin, Jie Yan
Published Online: Aug 4 2008 2:34AM
DOI: 10.1002/anie.200800476