Cambridge experiment discovers potential new way to tackle disease

A professor of nano-photonics at the University of Cambridge thinks a new discovery could lead to the creation of a nano-robotic system to fight off disease. In an experiment measuring the temperature and colour change of nanoparticles, Jeremy Baumberg realised a pump type mechanism was created from the reaction temperature-responsive polymer that can communicate with another, sense their environments, and even find their way through water. Baumberg believes they can be used to built robot mechanism to filter cells in the body to fight disease.

Pretty much everyone agrees: Ants are annoying. But the tiny pests have a big strength; they produce really big forces for a creature so small. Just think of a row of workers dragging a leaf to their nest for dinner. Now, think of a row of infinitesimal "ants" exerting huge pressure to, say, push their way into living cells and fight off a disease. That's what Jeremy Baumberg, a physicist and professor of nanophotonics at the University of Cambridge, thinks his newest discovery — tiny machines mere billionths of a meter wide — could one day accomplish.

Baumberg wasn't looking to discover the world's smallest engine. He was working on nanotechnology to make large screens change color when he noticed something strange.

At room temperature, charged gold particles that had been coated with a temperature-responsive polymer called pNIPAM, then placed in a gel, attracted water. But when they were heated the particles unexpectedly collapsed, expelling that water and clinging tightly together. Upon cooling again, they pushed apart quickly and with massive force. It took less than a nanosecond for the particles to push apart. "It's too fast for us to measure at the moment," says Baumberg.

The key thing that he and his research team recognized was that when the nanoparticles shook off water, they tightened into what could be thought of as a really small spring with plenty of potential energy. Cooled just a bit, they snapped back to their original form with an unusually large amount of force. (The nanoparticles also changed color when they heated and cooled, from red to blue and back again.)

Baumberg thinks that the phenomenon could be used to create nano-engines that work like pumps, communicate with one another, sense their environments, and even find their way through water. Because the number of particles can be controlled, they could be used to build different, tiny machines that can't be detected by the naked eye. The researchers called their find, which was recently published in the journal PNAS, actuating nano-transducers (ANTs).