Dumbbells lend weight to molecular machines

An international team of chemists has devised a method that could allow them to organise tiny molecular machines on a surface to build devices that pack in thousands of times as many switching units than is possible with a conventional silicon chip.

Fraser Stoddart from the University of California Los Angeles and his colleagues have designed and made numerous molecules based on hanging ring-shaped molecules on other chain-like molecules and loops. By incorporating functional chemical groups along the length of the chain or around these loops, they have shown that it is possible to make the molecular beads switch between these various functional groups using heat, light, or electricity. The ultimate aim of creating such molecular-scale devices is to use them as switching units or logic gates in a future computer based on molecules instead of silicon chips.

Before that will be possible, however, the nanoscientists must find a way to organise arrays of these molecules on a surface so that input and output connections can be made between the molecules and the outside world.