MEMS, MOEMS, Nano, and Bionanotechnologies - Applied Optics Fundamentals and Device Applications - page 323

MEMS is the integration of mechanical elements, sensors, actuators, and
electronics on a common silicon substrate through microfabrication technol-
ogy. While the electronics are fabricated using IC process sequences (e.g.,
CMOS, Bipolar, or BICMOS), the micromechanical components are fabri-
cated using compatible “micromachining” processes that selectively etch
away parts of the silicon wafer or add new structural layers to form the
mechanical and electromechanical devices (see Figure 7.1).
MEMS promises to revolutionize nearly every product category by bring-
ing together silicon-based microelectronics with micromachining technol-
ogy, making possible the realization of complete systems-on-a-chip. MEMS
is an enabling technology allowing the development of smart products, aug-
menting the computational ability of microelectronics with the perception
and control capabilities of microsensors and microactuators, and expanding
the space of possible designs and applications.
Microelectronic integrated circuits (ICs) can be thought of as the “brains”
of a system, and MEMS augments this decision-making capability with
“eyes” and “arms” to allow microsystems to sense and control the envi-
ronment. Sensors gather information from the environment through mea-
suring mechanical, thermal, biological, chemical, optical, and magnetic
phenomena. The electronics then process the information derived from
the sensors and through some decision-making capability direct the actua-
tors to respond by moving, positioning, regulating, pumping, and filtering,
thereby controlling the environment for some desired outcome or purpose.
Because MEMS devices are manufactured using batch fabrication tech-
niques similar to those used for ICs, unprecedented levels of functionality,
reliability, and sophistication can be placed on a small silicon chip at a rela-
tively low cost.

S4700 25.0 kV5.9 mm ×35 SE(U)

1.00 mm

FIGURE 7.1
MEMS structure. (Courtesy of the MEMS and Nanotechnology Exchange.)