Thursday, March 09, 2006

Mini-Robots for Nano Construction

Tiny robots can operate on single cells and assemble microelectronics -- and could lead to cheap nanoscale manufacturing.

By Kevin Bullis

New robots -- about the size of a pair of dice -- can assemble microcircuits, deliver injections to individual cells, and probe the molecule-scale world, according to a final report released last month on a European micro-robotics project called Micron. The work could eventually lead to teams of such robots automating work on the molecular scale, first for research projects and prototype assembly, and eventually for industrial applications, such as testing drugs and building consumer electronics.

The goal of the European project, which involved eight groups from seven countries, was to develop several small robots, each equipped with a specialized tool, and to show that the robots could work together to complete a task that a single robot working alone couldn't do. The researchers managed to develop several tools, including micromanipulators, an atomic force microscope (AFM) probe, and a precise "syringe chip" for injecting cells. But they did not achieve the teamwork goal -- they ran out of time and money before getting more than one of a handful of prototypes working perfectly.

Nevertheless, "it looks like they've made a great amount of progress. They're pretty sophisticated robots," says Ron Fearing, professor of electrical engineering and computer sciences at UC Berkeley, who is also developing tiny robots. "It will start to be really interesting when they get dozens of robots working together," he says. "But it's a pretty impressive accomplishment just having a couple of those things working."

In an experiment that used a robot to inject fluid into cells, a process scientists might use to study DNA or the effects of new drugs, the researchers first fixed in place a single cell using traditional equipment. After the robot filled its syringe with fluid, it was guided to the cell by a human controller, and injected a precise amount of fluid into the cell (small enough that the cell would not burst). The liquid was designed to fluoresce once metabolized by the cell, confirming that the cell had survived the operation.

Once the researchers have more working robots, the robots could do all the required steps automatically, says Jörg Seyfried, head of Micromechatronics and Microrobotics at the University of Karlsruhe, Germany, the lead institution in the group. One robot might use an onboard digital camera (developed during the project) to locate the cells in a Petri dish. Another would find and hold one cell in place, while a third robot would perform the injection, guided by image-analysis software also developed during the project.