TR10: Biological Machines
Michel Maharbiz's novel interfaces between machines and living systems could give rise to a new generation of cyborg devices.
A giant flower beetle flies about, veering up and down, left and right. But the insect isn't a pest, and it isn't steering its own path. An implanted receiver, microcontroller, microbattery, and six carefully placed electrodes--a payload smaller than a dime and weighing less than a stick of gum--allow an engineer to control the bug wirelessly. By remotely delivering jolts of electricity to its brain and wing muscles, the engineer can make the cyborg beetle take off, turn, or stop midflight.
The beetle's creator, Michel Maharbiz, hopes that his bugs will one day carry sensors or other devices to locations not easily accessible to humans or the terrestrial robots used in search-and-rescue missions. The devices are cheap: materials cost as little as five dollars, and the electronics are easy to build with mostly off-the-shelf components. "They can fly into tiny cracks and could be fitted with heat sensors designed to find injured survivors," says Maharbiz, an assistant professor at the University of California, Berkeley. "You cannot do that now with completely synthetic systems."
Maharbiz's specialty is designing interfaces between machines and living systems, from individual cells to entire organisms. His goal is to create novel "biological machines" that take advantage of living cells' capacity for extremely low-energy yet exquisitely precise movement, communication, and computation. Maharbiz envisions devices that can collect, manipulate, store, and act on information from their environments. Tissue for replacing damaged organs might be an example, or tables that can repair themselves or reconfigure their shapes on the basis of environmental cues. In 100 years, Maharbiz says, "I bet this kind of machine will be everywhere, derived from cells but completely engineered."
The remote-controlled beetles are an early success story. Beetles integrate visual, mechanical, and chemical information to control flight, all using a modicum of energy--a feat that's almost impossible to reproduce from scratch. In order to deploy a beetle as a useful and sophisticated tool like a search-and-rescue "robot," Maharbiz's team had to create input and output mechanisms that could efficiently communicate with and control the insect's nervous system. Such interfaces are now possible thanks to advances in microfabrication techniques, the availability of ever smaller power sources, and the growing sophistication of microelectromechanical systems (MEMS)--tiny mechanical devices that can be assembled to make things like radios and microcontrollers.