Researchers at the University of Cambridge have developed the world’s tiniest engine – so small it could be used to enter living cells in order to fight disease. The nanoscale engine measures a few billionths of a metre across, and uses light to power itself. It’s been christened the ANT, or actuating nano-transducer.
Professor Jeremy Baumberg from the Cavendish Laboratory, who led the research, said: “Like real ants, they produce large forces for their weight. The challenge we now face is how to control that force for nano-machinery applications.” “We can get 10 nano-Newton forces, about ten to a hundred times more force per unit weight than any known other machine, from jet engines to molecular motors,” researcher Jeremy Baumberg told The Washington Post.
The prototype device is made of tiny charged particles of gold, bound together with temperature-responsive polymers. When heated to a certain temperature with a laser, the nano-engine stores large amounts of elastic energy, and the gold nanoparticles bind together into tight clusters. When it’s cooled the gold nanoparticles are quickly pushed apart, like a spring.
“It’s like an explosion,” said Dr Tao Ding from Cambridge’s Cavendish Laboratory. “We have hundreds of gold balls flying apart in a millionth of a second when water molecules inflate the polymers around them.” The research team is in discussion with private companies with the aim of commercialising the technology for microfluidics bio-applications. “Our main challenge is how to build a device that harnesses the forces for motion in one direction – a bit like a piston on a steam engine,” Baumberg told the Washington Post. “Currently the force just expands and contracts in all directions.”
