An Introduction to mems (Micro-electromechanical Systems)

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Micro-optoelectromechanical systems (MOEMS) is also a subset of MST and together with 

MEMS forms the specialized technology fields using miniaturized combinations of optics, 

electronics and mechanics.  Both their microsystems incorporate the use of microelectronics 

batch processing techniques for their design and fabrication.  There are considerable overlaps 

between fields in terms of their integrating technology and their applications and hence it is 

extremely difficult to categorise MEMS devices in terms of sensing domain and/or their 

subset of MST.  The real difference between MEMS and MST is that MEMS tends to use 

semiconductor processes to create a mechanical part.  In contrast, the deposition of a material 

on silicon for example, does not constitute MEMS but is an application of MST. 

 

Transducer 

A transducer is a device that transforms one form of signal or energy into another form.  The 

term transducer can therefore be used to include both sensors and actuators and is the most 

generic and widely used term in MEMS. 

 

Sensor 

A sensor is a device that measures information from a surrounding environment and provides 

an electrical output signal in response to the parameter it measured.  Over the years, this 

information (or phenomenon) has been categorized in terms of the type of energy domains but 

MEMS devices generally overlap several domains or do not even belong in any one category.  

These energy domains include: 

•

•

 Thermal 

•

 Chemical  - concentration, composition, reaction rate 

 Radiant 

- electromagnetic wave intensity, phase, wavelength, polarization 

•

 Magnetic  - field intensity, flux density, magnetic moment, permeability 

 Electrical  - voltage, current, charge, resistance, capacitance, polarization [4,5,6,7] 

 

Actuator 

An actuator is a device that converts an electrical signal into an action.  It can create a force to 

manipulate itself, other mechanical devices, or the surrounding environment to perform some 

useful function. 

 

2.3  History 

The history of MEMS is useful to illustrate its diversity, challenges and applications.  The 

following list summarizes some of the key MEMS milestones [8]. 

 

1950’s 

1958 

Silicon strain gauges commercially available 

1959 

presentation at California Institute of Technology.  He issues a public challenge by 

offering $1000 to the first person to create an electrical motor smaller than 1/64

th