Mini Force Field Steers Swarms of Microbots
KTSDESIGN/Science Photo Library/Corbis
Good news for unemployed tiny robots this week: Researchers at Purdue University have come up with a way to both power and control super-miniaturized individual robots — each about the size of a dust mite — by using magnetic force fields.
According to the research team, headed by mechanical engineering professor David Cappelleri, the new technique would allow for swarms of microbots to manage complex tasks that require cooperative behavior. Previous attempts at similar microbot systems have only been able to move groups of tiny bots in unison, researchers say.
“The reason we want independent movement of each robot is so they can do cooperative manipulation tasks,” says Cappelleri in press materials issued by the university. “Think of ants. They can independently move, yet all work together to perform tasks such as lifting and moving things. We want to be able to control them individually so we can have some robots here doing one thing, and some robots there doing something else at the same time.”
To address the issue, the Purdue team developed a system of magnetic fields generated by an array of tiny planar coils in the robots’ “workspace.” The coils produce localized magnetic fields that can be used to guide the robots individually, as opposed to a global filed that would move the ‘bots as a group.
What’s more, the magnetic fields actually power the robots as well. The radically miniaturized machines are too small for batteries, so onboard power isn’t an option at this scale. The microbot models used in the study are magnetic disks about 2 mm in diameter — about twice the size of a pinhead. But the team says the technology will work with machines as small as 250 microns, or 0.25 mm in diameter.
The technology could have practical applications in manufacturing and medicine. For example, microbots equipped with probe-like “force sensors” could be used in biopsies, crawling around the bottom of a petri dish to detect cancer cells.
Findings are detailed in a research paper published this month in the journal Micromachines. Here’s a video of the li’l fellers in action.