Inexpensive, matchstick-sized devices with no moving parts could serve as cheap, power-efficient substitutes for small electric motors found in consumer products ranging from microwave ovens to cars. These devices-under development by NanoMuscle in Antioch, CA-translate electronic signals into linear motion without the need for bulky magnets, coils, spindles and position sensors. The devices consist of off-the-shelf microprocessors attached to small metal strips, which are connected with wires made of shape memory alloy. (This alloy, used in most cell-phone antennas, changes shape in response to an electrical signal.) In the devices, proprietary software regulates the processor's electrical signal to achieve a given effect-say, to close a doll's eyes halfway.

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