Joined: 16 Mar 2004
|Posted: Wed Jul 25, 2007 2:43 pm Post subject: 150-year-old nanomachine
Scientists have brought to life a tiny machine that was first conceived nearly 150 years ago.
University of Edinburgh physicists have created a machine that could eventually lead to lasers moving objects remotely.
The idea first came to the great British scientist James Clerk Maxwell, who is ranked among other luminaries like Isaac Newton and Albert Einstein for his contributions to science in the 19th century.
His plan for an atom-sized device, known as Maxwell’s Demon, could trap molecules as they moved in a specific direction.
Now the University of Edinburgh team, inspired by Maxwell’s experiments in 1867, have been able to create the ‘nanomachine’ for the first time, but used their own ‘demon’ inside to capture the molecules as they moved.
The work, published in the 1 February issue of the journal Nature, could ultimately lead to scientists harnessing the energy of the molecules to shift solid objects from a distance.
Professor David Leigh, of the University of Edinburgh's School of Chemistry, said: "Our machine has a device - or ‘demon' if you like - inside it that traps molecule-sized particles as they move in a certain direction.
"Maxwell reasoned that if such a system could ever be made, it would need energy to work. Without energy, it might appear that the perpetual motion of the molecules could power other devices in the same way as a windmill, but Maxwell reasoned that this would go against the second law of thermodynamics.
"As he predicted, the machine does need energy and in our experiment it is powered by light. While light has previously been used to energise tiny particles directly, this is the first time that a system has been devised to trap molecules as they move in a certain direction under their natural motion. Once the molecules are trapped they cannot escape," Leigh explained.
Future of lasers
Future applications for the nanotechnology machine include trapping molecules to generate a force in front of a solid object using a laser pen.
By shining the pen in the direction you want the object to move, the force of the molecules could be harnessed to push the object along.
The invention of the nanotechnology machine builds on previous work at the university in which scientists were able to move a droplet of liquid up a slope using molecular force.
"Last year was the 175th anniversary of James Clerk Maxwell's birth in Edinburgh, so it is fitting that advances in science mean that we can finally create a machine like the hypothetical one he pondered over so long ago," said Professor Leigh.
"Maxwell was instrumental to our understanding of light, heat, and the behaviour of atoms and molecules. Without the foundations that he laid down a century-and-a-half ago, the science that we are doing today would not have been possible."
Story first posted: 2nd February 2007.