Tiny, self-assembling robots can swim and clamp onto particles and then release them when subjected to the right magnetic fields.

These mini robotic doughnuts spontaneously form from metal particles floating between a layer of oil and water, and could potentially be used to manipulate chemical reactions, deliver medical treatments in the body or clean surfaces.

“It’s really counter intuitive,” said physicist Igor Aranson, co-author of a study in Nature Materials, Aug. 7. “There is nothing fancy about magnetic particles, you can just buy them. But if you pour them on the surface of a liquid, you ...

The iPhone version of Final Fantasy Tactics is just as dramatic as the original game.
(Screengrab: Jason Schreier/Wired.com)

A single flaw makes the otherwise fantastic mobile version of Final Fantasy Tactics nearly unplayable.

Developer Square Enix released the iOS port of its classic strategy role-playing game last week for iPod Touch, iPhone 3GS and iPhone 4 (reviewed). Unfortunately, the mobile version of Final Fantasy Tactics Wired.com tested suffers from brief bouts of graphical slowdown that plague every action.

Every time one of your characters swings a sword, casts a spell or moves...