These nanosubmarines are powered by tiny propellers and light

These nanosubmarines are powered by ultraviolet light

Molecular chemist James Tour is a bit of an expert at building tiny vehicles. For the last decade, he's been building nanocars - single-molecule cars that have four wheels, axles and suspension and can 'drive' across a surface.

His newest creation, however, goes below the waves instead - it's a single-molecule nanosubmarine, powered by ultraviolet light. Its body consists of 244 atoms, carefully arranged in a 20-step chemical process.

When the submarine is exposed to light, the connection holding the propeller to the body alternates between double- and single-bond states, allowing it to turn. Every full rotation drives it forward 18 nanometres.

Throwing Basketballs

While that doesn't sound like a lot, it operates at more than a million rpm, giving it a top speed of a little under an inch a second. "These are the fastest-moving molecules ever seen in solution," Tour said.

Unfortunately, it can't steer yet. But the subs prove that the molecular motors can push through solutions of moving molecules - no easy task.

"This is akin to a person walking across a basketball court with 1,000 people throwing basketballs at him," said Tour.

Eventually, it's hoped that the submarines could carry cargoes for medical and other purposes. Victor García-López, who worked on the submarines with Tour and authored a paper describing the breakthrough in Nano Letters, said: "This is the first step, and we've proven the concept. Now we need to explore opportunities and potential applications."

Image credit: Loïc Samuel/Rice University

Duncan Geere
Duncan Geere is TechRadar's science writer. Every day he finds the most interesting science news and explains why you should care. You can read more of his stories here, and you can find him on Twitter under the handle @duncangeere.