Nanobots have been featured in the realm of science fiction since the advent of the genre – tiny robots manipulating the world around us. But today, like so many of sci-fi’s wildest dreams, scientists are actually making the fantasy into a reality and developing machines the size of complex molecules.
One day these nanobots could be used by doctors to enter living cells to make repairs.
The idea is reminiscent of the 1966 movie Fantastic Voyage in which a surgical task force in a tiny submarine is shrunk and then injected into the bloodstream of a scientist in order to repair damage to his brain.
It also brings to mind the sci-fi ride called Body Wars at Epcot in Orlando, Florida. The viewer experiences what it would be like to shrink to the size of a blood cell and witnesses, first hand, what it looks like inside the body as cells fight against a splinter.
There have been countless renditions of the journey inside the body and the potential for healing on a microscopic level, but there’s always been one huge obstacle holding back such an endeavor in medical sciences – thus far, power sources developed for nanobots haven’t been effective.
The bots lack speed and strength and they have difficulty moving through liquids, which is an absolutely necessary ability if they are ever to enter the human body with any success. Plus, it currently takes a number of minutes just to move a nanobot’s “arm” even a tiny bit.
But, like with all the best sci-fi stories – that may all be about to change…
The ANT Engine
Scientists at Cambridge University in England have developed the smallest microscopic engine in existence, thus far – one, they say, that’s capable of driving nanobots into the future.
The Cambridge prototype device is known as an actuating nano-transducer – or ANT.
This latest nano-motor has been built using microscopic charged particles of gold only 60 nanometers in diameter. That’s about a thousandth of the width of a human hair.
The gold particles are held together by a gel that utilizes a temperature-sensitive polymer called pNIPAM.
The whole “engine” is, then, suspended in water.
ANT Springs Forward
The key to ANT’s function is a laser that heats the nano-engine as it’s held in water. ANT then begins storing the mechanical energy as it emerges from the tiny gold particles that the heat forces into tightly-bonded clusters.
When cooled, the polymer gel absorbs the surrounding water and rapidly expands. This expansion works like a spring, pushing the gold nanoparticles apart.
When heated again, the process repeats itself. This mini-explosion then propels the nanobot.
The Cambridge team explains that ANT generates a propulsive force on a microscopic scale that’s about 100 times greater, per unit weight, than any known motor or muscle.
In the Proceedings of the National Academy of Sciences, the leader of the Cambridge project, Professor Jeremy Baumberg, explained, “Like real ants, [ANTs] provide large forces for their weight. The challenge we now face is how to control the force for nano-machinery applications.”
In other words, the bots in their current state, once set in motion, go careening all over the place in a directionless frenzy.
Thus, an ANT steering mechanism is now needed.
The Direction of ANT
Even as ANT remains incomplete, the research team is already working with Cambridge’s commercialization team on putting the technology to work.
Perhaps the most interesting application involves microfluidic chips. These chips are used in synthesizing pharmaceuticals as well as in a number of biochemical processes.
A microfluidic chip is a set of micro-channels etched or molded into a material. The micro-channels forming the chip work in coordination to mix, pump, sort, and control a biochemical environment.
Currently, the pumps and valves are made with hydraulics, limiting the complexity of the tasks they can perform.
But Professor Baumberg thinks the pumps and valves can now be made using ANT technology.
He foresees each ANT controlled by a beam of light, with possibly thousands of ANTs on a single chip.
The possibilities of this technology seem as endless as the science fiction storylines that it inspired in film and television.
Perhaps, in the not-too-distant future, there will come a day when “fantastic voyages” though the human body become quite routine rather than a thing of fantasy.