24-Layer Rotary Varactor
The picture above is a 24-layer rotary varactor fabricated in nickel using the Electrochemical Fabrication (EFAB®) technology. Scanning electron micrograph courtesy of Adam L. Cohen, Microfabrica Incorporated (www.microfabrica.com), U.S.A. For details of the EFAB® technology, see chapter 6, volume II, of "The MEMS Handbook," ed. M. Gad-el-Hak, second edition, CRC Taylor & Francis, Boca Raton, Florida, 2006.
Microelectromechanical systems (MEMS) refer to devices that have characteristic length of less than 1 mm but more than 1 micron, that combine electrical and mechanical components, and that are fabricated using integrated circuit batch-processing technologies. The multidisciplinary field has witnessed explosive growth during the last decade. Global funding for micro- and nanotechnology research and development quintupled from $432 million in 1997 to $2.2 billion in 2002. In 2004, the U.S. National Nanotechnology Initiative has a budget of close to $1 billion, and the worldwide investment in nanotechnology exceeded $3.5 billion. In 10 to 15 years, it is estimated that micro- and nanotechnology markets will represent $340 billion per year in materials, $300 billion per year in electronics, and $180 billion per year in pharmaceuticals.