Micropower

Micropower describes the work that researchers at several universities are doing to develop very small electric generators and prime movers or devices to convert heat or motion to electricity, for use close to the generator. These devices offer the promise of a power source for portable electronic devices which is lighter weight and has a longer operating time than batteries. Micropower differs from microgeneration in being concerned with universities, mobility and milliwatts or watts rather than individuals, homes and kilowatts.

The components of any turbine engine — the gas compressor, the combustion chamber, and the turbine rotor — are fabricated from etched silicon, much like integrated circuits. The technology holds the promise of ten times the operating time of a battery of the same weight as the micropower unit, and similar efficiency to large utility gas turbines. Researchers at Massachusetts Institute of Technology have thus far succeeded in fabricating the parts for such a micro turbine out of six etched and stacked silicon wafers, and are working toward combining them into a functioning engine about the size of a U.S. quarter coin.

Researchers at Georgia Tech have built a micro generator 10 mm wide, which spins a magnet above an array of coils fabricated on a silicon chip. The device spins at 100,000 revolutions per minute, and produces 1.1 watts of electrical power, sufficient to operate a cell phone. Their goal is to produce 20 to 50 watts, sufficient to power a laptop computer.

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