Microrobots individually controlled using 'mini force fields'

New York: US scientists have developed a technology likened to "mini force fields" to independently control individual microrobots operating within groups, an advance aimed at using the tiny machines in areas including manufacturing and medicine.

Until now it was only possible to control groups of microrobots to move generally in unison, said David Cappelleri, an assistant professor of mechanical engineering at Purdue University.

"The reason we want independent movement of each robot is so they can do cooperative manipulation tasks," he said.

"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."

Cappelleri's team developed a system for controlling the robots with individual magnetic fields from an array of tiny planar coils.

"The robots are too small to put batteries on them, so they can't have onboard power," Cappelleri said. "You need to use an external way to power them. We use magnetic fields to generate forces on the robots. It's like using mini force fields."

The microrobots are magnetic disks that slide across a surface. While the versions studied are around 2 mm in diameter -- about twice the size of a pinhead -- researches aim to create microrobots that are around 250 microns in diametre, or roughly the size of a dust mite.

The study is detailed in a research paper appearing this month in the journal Micromachines.

Postdoctoral research associates Sagar Chowdhury and Wuming Jing co-authored the paper along with Cappelleri.