SQUADRONS of robotic machines have taken flight in recent years, ranging from unmanned aerial vehicles which patrol in Iraq and Afghanistan to experimental machines not much bigger than insects. But it remains hard to shrink engines, batteries, mechanical actuators and control electronics to the point where they are small and light enough to fly without impairing their performance. It would be nice, therefore, if all the on-board paraphernalia of propulsion and control could be dispensed with, leaving an unencumbered device that is still capable of directed flight.
That is exactly what Behrad Khamesee and his colleagues at the University of Waterloo, in Ontario, have managed. They have built a micro-robot that levitates, rather like a Dalek in “Dr Who”. And instead of having an old sink-plunger doubling as its arm, their robot has a useful set of grippers.
The researchers use magnetic levitation to lift their robot, which is a mere 6mm tall. The process, which relies on magnetic fields attracting or repelling each other, is more usually applied to large machines such as maglev trains, and then with some kind of guide rail or tether to prevent the machine from drifting too far off track. Dr Khamesee’s robot, however, is completely untethered and can be positioned to an accuracy measured in a few thousands of a millimetre.
The team are now working on improving the robot’s precision and expanding the volume in which it can operate. They are also looking at the possibility of using the system to control even smaller robots that could be used within the body, for drug delivery or microsurgery. Imagine opening your mouth and watching one levitate inside.
