March 1, 2002

Walking Small

MIT researchers design robots to automate tiny tasks.

By David Cameron

In an effort to automate the many important yet mundane tasks involved with materials science, a team at MIT's BioInstrumentation Laboratory is building an army. Led by researcher Sylvain Martel, the group is developing a fleet of thumb-sized robots that, according to Martel, will be able to measure and assemble structures at a molecular level, which would be a welcome development for researchers.

So far, prototypes of these robots wired to an external computer have demonstrated their ability to take 4,000 nanoscale steps per second-that is, steps that are only a few billionths of a meter each. Individual components-the embedded computer, a measuring device, an infrared transmitter-have also been put through their paces. The group is now integrating all the parts into a complete system they call NanoWalkers and expects soon to have the first fully autonomous, wireless prototypes up and operating. "Just to be safe, I'd say our first prototype will be ready in approximately three months," Martel says. "But it may be even sooner."

The test platform for this robotic fleet is a square chamber, about as wide as a poker table. The robots-each 32 millimeters across-are placed inside on a chromium-coated surface that powers the electronics in each NanoWalker. A central computer mounted on top of the platform coordinates each robot's location. Once a robot reaches its designated place on the surface, it begins its assigned task.

The machines are designed to be adapted for a number different types of automated research tasks-from measuring and manipulating molecules to developing new pharmaceuticals by testing molecules against potential drug targets. "The point is to have a versatile device that can be used for many different types of research," Martel says.

The prototypes are each rigged with a specially designed scanning tunneling microscope, a device that can not only create images of individual atoms but also move them. The microscope can make up to 200,000 measurements per second, and the microcomputer embedded in each robot can potentially perform 48 million instructions per second.

Martel envisions one hundred or more robots deployed on a project, each equipped with a different instrument, working on separate but related tasks. For example, he says they could help to develop new polymers, another project in the BioInstrumentation Lab. While one NanoWalker tests a material's strength, another would measure its optical properties. Both would transmit their results to the central computer, which would incorporate the information and then issue new directions.

According to Ian Hunter, head of MIT's BioInstrumentation Lab, the NanoWalker project reflects the lab's search for tools to automate the scientific method itself. "This will be an age where an entire program of research will be carried out by one machine as opposed to a building full of separate machines," he says.

It will still be some time before this "factory" is in full swing, but Martel is content to take some very small steps to get there.