Researchers at the Department of Energy's Sandia National Laboratories in Albuquerque, N.M., have developed what may be the world's smallest robot. Fueled by three watch batteries, the device "turns on a dime and parks on a nickel," said Steve Martin, manager of Sandia's Sensor Technologies Department.
The mini-robot measures 0.25 in.3 and weighs less than an ounce (see the figure). Powered by an 8k ROM processor, it rides on track wheels. It also incorporates a temperature sensor and two motors that drive the wheels. According to the development team, it may be the smallest autonomous untethered robot ever created.
Though it's still in the early development stage, Sandia scientists Doug Adkins and Ed Heller believe this device will eventually be able to perform many of the difficult tasks handled by larger robots today. For example, it could locate and disable land mines or detect chemical and biological weapons. Its small size will let it scramble through pipes and stealthily maneuver through buildings to detect chemical plumes or human movement, too.
Current research supports Laboratories Directed Research and Development (LDRD) work started in Sandia's Intelligent Systems Sensors and Controls Department. In 1996, this project unveiled the Mini Autonomous Robot Vehicle (MARV), a 1-in.3 version of the current device. This larger model contained all the necessary power, sensors, computers, and controls. Initially, the MARV mini-robots were built from commercial parts using conventional machining techniques. Improved versions had bodies made of pc boards. Each offered an obstacle-detector sensor, a radio, a temperature sensor, and a battery.
Taking the MARV research to the next level, researchers revised packaging techniques, wheel design, and material choice to shrink the device to its current size. Since packaged components consume more space, electronic components in die form rather than packaged form were used. The commercially available unpackaged components were assembled onto a simple multichip module on a glass substrate.
The researchers used a material-building method called stereolithography to form the device's body. This process repeatedly deposits a thin, laser-cured polymer layer, producing a strong, lightweight material that can be formed into complex shapes. Cavities are formed in the robot body for batteries, the electronics-embedded glass substrate, axles, motors, and switches.
While earlier devices employed standard wheels, this model's track wheels enhance maneuverability—they can maneuver through a field of dimes and nickels at 20 in. per minute. Ongoing research is examining communication between the mini-robots and the relay of information to manned stations. Scientists expect the devices to eventually work together like a swarm of insects.
Researchers say the robots' need for three batteries ultimately limits their size. Projected improvements include infrared or radio wireless two-way communication capability, miniature video cameras, microphones, and chemical microsensors.
For more information about the mini-robot, visit www.sandia.gov.