And we're getting better at controlling them. Magnetic fields can stop and turn these bots on a dime — with a whole lot of room to spare.
The challenge is controlling individual bots. We'd like to have swarms of micro-bots cooperating to do complex tasks, but that requires magnetic fields fine enough to steer them one at a time.
To do this, scientists with Philips Research created a magnetic field that has a regular weak spot. The strong part of the field holds a whole group of magnetic screws still, while a second magnetic field in the weak spot turns an individual screw.
This demonstration isn't micro-scale yet, but it is promising. As machines get smaller, those rotating magnetic fields are more efficient at moving them around than pushing or pulling on them. The researchers say their system of strong and weak fields could control hundreds of machines simultaneously.
And even if the machines don't scale down immediately, the researchers see possible medical applications for right now. The magnetic screws could deliver precise, adjustable radiation treatments without major surgery or batteries.