Microscopic 'Hands' For Building Tomorrow’s Machines

In the new study, David Gracias and colleagues note that researchers have long sought to develop chemically triggered microscopic devices that can manipulate small objects with precision. Chemical actuation occurs in biological machinery and enables autonomous function in nature with high specificity and selectivity. Although other scientists have made experimental “grippers” in the lab, these devices generally require the use of batteries and wiring, making them hard to miniaturize and maneuver in small spaces and convoluted conduits.

The researchers describe development of tiny metallic microgrippers shaped like a hand that work without electricity. The grippers are about 0.03 inches wide when open — smaller than the diameter of a grain of sand and made from a gold-coated nickel “palm” joined by six pointy metallic “fingers.” The addition of certain chemicals triggers the hands to open or close. In laboratory studies, the scientists demonstrated that the grippers could grasp and release tiny pipes and glass beads and transport these objects to distant locations with the aid of a magnet, showcasing their potential for pick-and-place operations that are ubiquitous in manufacturing, they say.

They also say that this demonstration is also a step toward the development of Micro Chemo Mechanical Systems (MCMS) in contrast to the already well established field of Micro Electro Mechanical Systems (MEMS); the main difference being that the tools are triggered by chemistry as opposed to electricity.