MICRO ELECTRO-MECHANICAL SYSTEM
Microelectromechanical systems (MEMS) (also written as micro-electro-mechanical, MicroElectroMechanical or microelectronic and microelectromechanical systems) is the technology of very small mechanical devices driven by electricity; it merges at the nano-
scale into nanoelectromechanical systems (NEMS) and nanotechnology. MEMS are also referred
to as micromachines (in Japan), or Micro Systems Technology - MST (in Europe).
MEMS are separate and distinct from the hypothetical vision of molecular nanotechnology or
molecular electronics. MEMS are made up of components between 1 to 100 micrometres in size
(i.e. 0.001 to 0.1 mm) and MEMS devices generally range in size from 20 micrometres (20
millionths of a metre) to a millimetre. They usually consist of a central unit that
processes data, the microprocessor and several components that interact with the outside
such as microsensors.
At these size scales, the standard constructs of classical physics are not always useful. Because of the large surface area to volume ratio of MEMS, surface
effects such as electrostatics and wetting dominate volume effects such as inertia or
thermal mass.
could make them—see, for example, Richard Feynman's famous 1959 lecture There's Plenty of
Room at the Bottom. MEMS became practical once they could be fabricated using modified
semiconductor device fabrication technologies, normally used to make electronics. These
include molding and plating, wet etching (KOH, TMAH) and dry etching (RIE and DRIE), electro
discharge machining (EDM), and other technologies capable of manufacturing small devices. An
early example of a MEMS device is the resonistor – an electromechanical monolithic
resonator.
The Defense Advanced Research Project Agency, that secretive band of Pentagon geeks that
searches obsessively for the next big thing in the technology of warfare, is 50 years old.
To celebrate, DARPA invited Vice President Dick Cheney, a former Defense Secretary well
aware of the Agency's capabilities, to help blow out the candles. "This agency brought forth
the Saturn 5 rocket, surveillance satellites, the Internet, stealth technology, guided
munitions, unmanned aerial vehicles, night vision and the body armor that's in use today,"
Cheney told 1,700 DARPA workers and friends who gathered at a Washington hotel to mark the
occasion. "Thank heaven for DARPA."
Created in the panicky wake of the Soviets' launching of Sputnik, the world's first
satellite, DARPA's mission, Cheney said, is "to make sure that America is never again caught
off guard." So, the Agency does the basic research that may be decades away fromttlefield
applications. It doesn't develop new weapons, as much as it pioneers the technologies that
will make tomorrow's weapons better.
So what's hot at DARPA right now? Bugs. The creepy, crawly flying kind. The Agency's
Microsystems Technology Office is hard at work on HI-MEMS (Hybrid Insect Micro-Electro-
Mechanical System), raising real insects filled with electronic circuitry, which could be
guided using GPS technology to specific targets via electrical impulses sent to their
muscles. These half-bug, half-chip creations — DARPA calls them "insect cyborgs" — would be
ideal for surveillance missions, the agency says in a brief description on its website.
Scientist Amit Lal and his team insert mechanical components into baby bugs during "the
caterpillar and the pupae stages," which would then allow the adult bugs to be deployed to
do the Pentagon's bidding. "The HI-MEMS program is aimed at developing tightly coupled
machine-insect interfaces by placing micro-mechanical systems inside the insects during the
early stages of metamorphosis," DARPA says. "Since a majority of the tissue development in
insects occurs in the later stages of metamorphosis, the renewed tissue growth around the
MEMS will tend to heal, and form a reliable and stable tissue-machine interface." Such bugs
"could carry one or more sensors, such as a microphone or a gas sensor, to relay back
information gathered from the target destination."
DARPA declined TIME's request to interview Dr. Lal about his program and the progress he is
making in producing the bugs. The agency added that there is no timetable for turning
backyard pests into battlefield assets. But in a written statement, spokeswoman Jan Walker
said that "living, adult-stage insects have emerged with the embedded systems intact."
Presumably, enemy arsenals will soon be well-stocked with Raid.
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