A set of five tiny fundamental parts can be assembled into a wide variety of functional devices including a tiny “walking” motor that can move back and forth across a surface or turn the gears of a machine. The work offers an alternative to current approaches to constructing robots, which largely fall into one of two types: custom machines that work well but are relatively expensive and inflexible, and reconfigurable ones that sacrifice performance for versatility.
The set of five millimeter-scale components can all be attached to each other by a standard connector. The parts include rigid and flexible types, along with electromagnetic parts, a coil, and a magnet. Using this simple kit of tiny parts, a motor was developed that moves an appendage in discrete mechanical steps that can be used to turn a gear wheel, and a mobile form of the motor that turns those steps into locomotion, allowing it to “walk” across a surface in a way that is reminiscent of the molecular motors that move muscles. These parts could also be assembled into hands for gripping or legs for walking and then later reassembled as those needs change. The “digital materials” can be reversibly joined, forming a kind of functional micro-LEGO®.
The new system is a step toward creating a standardized kit of parts that could be used to assemble robots with specific capabilities adapted to a particular task or set of tasks. Such purpose-built robots could then be disassembled and reassembled as needed in a variety of forms, without the need to design and manufacture new robots from scratch for each application.
The motor has an ant-like ability to lift seven times its own weight; if greater forces are required, many of the parts can be added to provide more strength. If the robot needs to move in more complex ways, the parts could be distributed throughout the structure. The size of the building blocks can be chosen to match their application; nanometer-sized parts to make nanorobots and meter-sized parts to make megarobots. Part types that contain millimeter-sized integrated circuits connect electrical signals in three dimensions.
A novel machine was developed to fabricate the parts that is a cross between a 3D printer and the pick-and-place machines that manufacture electronic circuits. Unlike either of those, this one can produce complete robotic systems directly from digital designs.