Making devices small has long had engineering, scientific, and aesthetic motivations.
For example, John Harrison’s quest  to make a small (e.g., hand-sized)
chronometer in the 1700s for nautical navigation was motivated by the desire to
have an accurate time-keeping instrument that was insensitive to temperature,
humidity, and motion. A small chronometer could meet these objectives and allow
for multiple instruments on a ship for redundancy and error averaging. A number
of technological firsts came from this work, such as the development of the roller
Within a period of a few decades, the ¯eld of materials science and engineering
has emerged as a focal point for developments in virtually all areas
of engineering and applied science. The study of thin film materials has
been one of the unifying themes in the development of the ¯eld during this
period. As understood here, the area encompasses ¯lms bonded to relatively
thick substrates, multilayer materials, patterned ¯lms on substrates
and free-standing ¯lms.
Over many years, RF-MEMS have been a hot topic in research at the technology
and device level. In particular, various kinds of mechanical Si-MEMS resonators
and piezoelectric BAW (bulk acoustic wave) resonators have been developed. The
BAW technology has made its way to commercial products for passive RF filters,
in particular for duplexers in RF transceiver front ends for cellular communications.
Beyond their use in filters, micromachined resonators can also be used in
conjunction with active devices in innovative circuits and architectures.
Micromechanical photonics is evolvingin interdisciplinary research and engineering
fields and merging independently developed technologies based on
optics, mechanics, electronics, and physical/chemical sciences. Manufacturing
technologies such as those of semiconductor lasers, surface micromachining
and bulk micromachiningare promotingtec hnology fusion.