Pointing the Way for Micro Motion

netjeff writes: "As reported in the 27 Oct 2001 issue of Science News, Japanese researchers have found a way to control movement of microtubules. They wanted to get the tubules to move around a circular track in one direction, but the tubules would move randomly. Their solution? Simply point the way. More precisely, etch arrowheads into the circular track, and the tubules will move in that direction only. A good example showing that building micro-machines requires a different way of thinking compared to building macro-machines."

Comments

why this works

[morcheeba]

Those little buggers are are good at following directions, that's why!

IANANTS (i am not a nano technology specialist)

Here's my guess: The funneling effect of the arrowhead allows more randomly-moving particles flow in that direction rather than the rather small reverse opening.

Said another way: Imagine you're standing in the middle of one the arrowheads, and you've got a fan. You'd get more wind blown into the angled down (arrowhead) exit rather than the small hole at the back of the arrowhead.

All this, of course, requires random motion of the particles. The motion must already be present; this shape just directs it.