The Flying Microbot: Batteries Not Included
|“We have developed a magnetically levitated micro-robot.” –Prof. Mir Behrad Khamesee|
Recently, we’ve shown you robots that are complex enough to take care of living things, and robots that are advanced enough to respond to thoughts. Those wacky Canadians at the University of Waterloo in Ontario, however, have decided to explore the other end of robotics. Simplify, man. Professor Mir Beharad Khamesee, director of the Maglev Microrobotics Lab, has created a micro robot without a power source or control wires — it’s basically just a pair of tiny tweezers. Oh, and it flies.
|This MEMS robot, just a few millimeters across, is dwarfed by a Canadian penny.|
The microbot is actually an example of a micro-electro-mechanical system (MEMS), tiny machines that work using electromagnetic techniques. They could be adapted for micro sized assembly, manipulating tiny scientific samples, or even performing microsurgery. Khamesee’s MEMS robot flies by using magnetism. The tweezers of the robot, or microgrippers, are attached to permanent magnets. These magnets are lifted by magnetic fields generated by electric coils. As those fields change, the robot flies through space. No strings, no engines, just magnets.
Watching it hover is almost eerie, like seeing a flying acrobat on an invisible trapeze:
With great precision comes great responsibility
The precision of the robot’s flight is remarkable. Sensor feedback is constantly guiding the coils controlling the magnetic field to adjust the robot’s movements. It can be positioned with an accuracy of 13 microns in a relatively large volume (18 cm3). The use of magnetic levitation (maglev) allows it to sit on irregular surfaces, or hover above a surface and travel without friction or adhesion. These are major improvements over other small scale robots that may move by sliding or rolling across a surface. The maglev robot won’t leave a trail or disturb what it manipulates. [Sort of like a tiny flying robotic boy scout]
That manipulation comes from the robot’s microgrippers. Here again, the Khamesee team has engineered its way around needing a power source. The microgrippers are opened and closed through the clever use of heat. A laser pointed at the tiny circle on the grippers will heat them and cause them to open. As the grippers cool, they close. A simple system, but precise enough to move items only 100 microns (0.1 mm) in diameter.
|The microgrippers will open as a laser heats them, and then close again when the laser is turned off.|
What makes the flying microbot unique, maglev flight and precision, will also make it useful. The high maneuverability of maglev flight will allow the robot to enter twisted and moving systems. Without control wires or a power source, it is essentially dust free. This makes the robot perfect for clean room applications. The controls of the robot: magnetic fields and lasers, can pass through transparent sealed surfaces, allowing it to be used for hazardous environments. Because it never touches anything besides the items it is manipulating, the robot is perfect for delicate work such as microsurgery.
“We are the first in the world to make such a floating robot equipped with micro-grippers. It can enter virtually any space and can be operated in a sealed enclosure by a person outside, which makes it useful for handling biohazardous materials or working in vacuum chambers and clean rooms.” –Khamasee
With a robot as elegantly simple as Khamasee’s, the promise of future applications is strong. Those in the industry may wish to check out his upcoming papers in IEEE and ASME. Once applications are proven, the next step would likely be a system for controlling multiple MEMS robots at the same time. As Prof. Khamasee’s work continues, the University of Waterloo may prove that simple solutions are often the best.