itionally, creating three-dimensional MEMS structures requires elabo- rate deposition and etching processes to build structures layer upon layer. StressedMetal MEMS offer a simpler approach. The process takes advantage of the stress that occurs in the thin-film deposition process. In thin-film depo- sition, extremely thin layers of metal film are deposited onto a substrate, such as glass or amorphous or silicon. PARC scientists have developed techniques to precisely control the stress within the layers of deposited metal. Litho- graphic techniques are used to etch patterns into the film layers. These patterns allow the metals to be released from the substrate. This technique can be used to create high volumes of self-assembling three-dimensional structures. NUTS AND BITS-TELECOM HARDWARE SOFTWARE, AND MORE Devices fabricated with the StressedMetal process offer significant cost and performance advantages over those created with more traditional approaches. StressedMetal devices can be cost-effectively created using surface micro- machining techniques and standard batch-manufacturing processes. They can be integrated on silicon substrates and may include fully active circuitry. Or designers can use less expensive substrates, such as glass. Such substrates offer the added advantage of being much larger than standard silicon wafers. To create StressedMetal MEMS structures, films are sputter deposited with an engineered built-in stress gradient. After lithographic etching is completed, the structures are released. The metal's inherent stress causes it to lift or curl into a designed radius of curvature, creating three-dimensional structures such as tiny coils, springs, or claws. PARC's StressedMetal MEMS have been used in a number of prototype applications. All use simple and conventional fabrication processes, are able to be produced with high reliability, and offer superior performance to con- ventional counterparts. For example, PARC's StressedMetal on-chip, out-of- plane inductor enables a new generation of radio