Sir Fraser Stoddart, Chuyang Cheng, and colleagues, Northwestern University, Evanston, IL, USA, have developed the first entirely artificial molecular pump. It mimics the pumping mechanism of proteins that move small molecules around living cells to metabolize and store energy from food. The artificial pump draws power from chemical reactions by driving molecules far away from the equilibrium from a low-energy state to a high-energy state.
The molecular pump threads rings around a nanoscopic chain and squeezes these rings together, with only a few nanometers separating them. The ring-shaped molecules repel one another under normal circumstances. The artificial pump is able to draw some of the energy of the chemical reaction and uses it to push the rings together. The molecular pump performs work repetitively for two cycles of operation.
At present, the artificial molecular pump is able to force only two rings together. The researchers believe that they can extend its operation to tens of rings and thereby store more energy. Ultimately, the researchers intend to use the energy stored in their pump to power artificial muscles and other molecular machines.