24-06-2013, 04:55 PM
MEMS Applications Overview
MEMS Applications.pdf (Size: 2.15 MB / Downloads: 60)
Introduction
Microelectromechanical systems (MEMS) are very small devices or groups of devices that can
integrate both mechanical and electrical components. MEMS can be constructed on one chip that
contains one or more micro-components and the electrical circuitry for inputs and outputs of the
components. The components include different types of sensors, transducers, actuators, electronics
and structures (e.g. gears, sliding mirrors, diaphragms). Each type of components is designed to
interface with an input such as light, gas molecules, and a specific type of radiation, pressure,
temperature, or biomolecules.
Macro vs. Micro
An equivalent of a MEMS device at the macro scale is the diaphragm gauge used to measure
pressures and pressure changes. Such a gauge consists of a mechanical component (the diaphragm)
and electrical components that supply an input and output voltage(s). As the diaphragm moves due
to changes in pressure, an output voltage proportional to the change in pressure is generated. Reduce
the size of the diaphragm and the related electrical components, place them all on the same
microchip, and you have a microelectromechanical system or MEMS. The above photographs
compare the macro pressure sensor to the MEMS sensor (left picture) and the diaphragms (right
pictures).
Some MEMS are as small as the head of a pin. MEMS components are even smaller – micro and
nano-size.
Objectives
State three fields in which MEMS devices are being used
State three applications of MEMS devices in the automobile industry
State three applications for MEMS in the medical field
What are MEMS?
Microelectromechanical systems (MEMS) are devices that can sense, think, act and communicate.
MEMS redirect light, pump and mix fluids, and detect the presence of molecules, heat, pressure or
motion (all of which have been done for years in a macro scale). Through the miniaturization of
these macro-sized devices and the ability to fabricate micro-sized devices in large numbers, the costs
of manufacturing have decreased.
A MEMS's small size allows it to be incorporated into a vast array of products. It can be included as
a component of an integrated circuit or embedded into materials during manufacturing. Such
characteristics permit the construction of more complicated systems and expand the potential
applications of MEMS.
MEMS are wide-ranging in their applications and construction. There can be one microdevice or
element on a single chip or millions of devices or elements on a single chip. The interaction of these
components working together makes up a microelectromechanical system or MEMS. MEMS
elements work independently as a solitary device or work together in large arrays or combinations in
order to perform complicated tasks.
A Note on Terminology
In the literal sense, MEMS means MicroElectroMechanical Systems - any microsystem that
integrates both electrical and mechanical components on the same chip. However, as terms
sometimes do, MEMS has evolved to refer to any microdevice or microsystem that is made using one
of the typical microfabrication technologies. This includes not only microelectromechanical, but also
microfluidics, micro-optics or any system made, at least in part, at the microscale.
Another term that represents all types of microsystems is MicroSystems Technology or MST. MST
is all encompassing. It includes any device, system or component fabricated at the microscale. MST
is not widely used in the United States. MEMS is the more common term and is used synonymously
with MST.