Thursday, 11 October 2007
Sceince Friction: Radical Tribology Breakthrough may lead to Friction Free Micro Machines.
Why do your hands heat-up when you rub them together? Why do you have to change your car tires ever 50,000 miles or so?
The answer, in the main, is found through the science of Tribology (or the study of friction). Rub things together and they heat up and eventually wear away to nothing.
There’s a lot of engineering science behind understanding friction. I wont go there.
What I will do here is talk about an area of high concept friction science called the Casimir Force (CF), which - without getting to technical - causes an attractive affect in the space between atom, so that molecules are drawn together as that move or flow across each other.
As the CF attracts each moving atom they rub together, thus heating and causing atoms to displace. Hence friction; hence wear.
But what if you could turn off the CF? Well, you get no friction, no ware! Things wouldn’t wear out. You wouldn’t have to change your car tires. Cells in your body wouldn’t rub together. You wouldn’t were out.
But what if you could reverse the CF in a controlled way? Atoms would move away from each other. You’d get levitation.
Science fiction (friction) right?
Scientists at the University of St Andrews have created an 'incredible levitation effect’ by engineering the CF so that it repels instead of attracts.
Their discovery could ultimately lead to frictionless micro-machines with moving parts that levitate. But they say that, in principle at least, the same effect could be used to levitate bigger objects too, even a person.
The force is due to neither electrical charge or gravity, for example, but the fluctuations in all-pervasive energy fields in the intervening empty space between the objects and is one reason atoms stick together, also explaining a “dry glue” effect that enables a gecko to walk across a ceiling.
Because the CF causes problems for nanotechnologists, who are trying to build electrical circuits and tiny mechanical devices on silicon chips, among other things, the team believes the feat could initially be used to stop tiny objects from sticking to each other.
Micro and even nanomachines could run smoother and with less or no friction at all.