Most of the proposed uses for MAVs are military; the funding, after all, is coming from the Department of Defense. But some workers in the field propose broader applications for tiny flying robots. Georgia Tech’s Michelson has suggested sending robot “terminators” after real-life insect pests, but suspects that the largest potential outlet for small aerial robots might be the toy market. Stanford’s Ilan Kroo leads a team developing a “mesicopter,” a multi-rotor electric helicopter. Currently of centimeter size but potentially much smaller, the mesicopter is shaped like a thin, square wafer with a little rotor at each corner. Essentially a flying microchip, a mesicopter’s motors, sensors, guidance, and telemetry systems would be etched in place in a single completely automatic manufacturing operation. Kroo’s team envisions swarms of mesicopters investigating the interiors of storms or the atmosphere of Mars.
The word “swarm” is particularly significant. Of course, it suggests insects, and much of the more startling MAV research is headed in the direction of emulating those successful products of natural selection. But it also alludes to nature’s profligacy. Many creatures that live in hazardous environments reproduce in huge numbers so that just a few may survive to maturity. MEMS manufacturing techniques imply a similar approach to machines. Rather than launch a single costly, sophisticated, man-carrying device to do a job, you would launch hundreds of simple, cheap robots. If most of them fail, no matter—they are expendable. Only one needs to complete the task.
A case in point, reminiscent of the wholesale egg-laying habits of marine creatures, is what Kris Pister of the Berkeley program calls “smart dust.” Consisting of various kinds of motion or chemical sensors, a power supply, a microprocessor, and a system of communication, all packed into the volume of a grain of coarse sand, these “motes” would be sprinkled randomly over a wide area to report back what they find. What would do the sprinkling and receive the reports? A MAV, of course.
The use of MEMS in the construction of miniature aircraft is likely to bring about, in the next decade, innovations that seem incredible today. The button turbojet could revolutionize propulsion, even if only for model aircraft builders. Soldiers fighting in blasted cities in central Asia will be grateful for the ability to look around corners with tiny airborne cameras. Children will shriek with delight as their robot wasps attack a neighbor’s action figure.
But will we have to wonder, even in civilian life, whether every persistent fly we encounter is carrying a listening device?