Microelectromechanical systems is the technology of microscopic devices, particularly those with moving parts. It merges at the nano-scale into nanoelectromechanical systems and nanotechnology, MEMS are also referred to as micromachines in Japan, or micro systems technology in Europe. They usually consist of a unit that processes data and several components that interact with the surroundings such as microsensors. MEMS technology is distinguished from molecular nanotechnology or molecular electronics in that the latter must also consider surface chemistry, the potential of very small machines was appreciated before the technology existed that could make them. MEMS became practical once they could be fabricated using modified semiconductor device fabrication technologies and these include molding and plating, wet etching and dry etching, electro discharge machining, and other technologies capable of manufacturing small devices. An early example of a MEMS device is the resonistor – an electromechanical monolithic resonator, silicon is the material used to create most integrated circuits used in consumer electronics in the modern industry. The economies of scale, ready availability of inexpensive high-quality materials, silicon also has significant advantages engendered through its material properties. In single crystal form, silicon is an almost perfect Hookean material, meaning that when it is flexed there is virtually no hysteresis and hence almost no energy dissipation. Even though the industry provides an economy of scale for the silicon industry, crystalline silicon is still a complex. Polymers on the hand can be produced in huge volumes. Metals can also be used to create MEMS elements, while metals do not have some of the advantages displayed by silicon in terms of mechanical properties, when used within their limitations, metals can exhibit very high degrees of reliability. Metals can be deposited by electroplating, evaporation, and sputtering processes, commonly used metals include gold, nickel, aluminium, copper, chromium, titanium, tungsten, platinum, and silver. The nitrides of silicon, aluminium and titanium as well as silicon carbide, alN crystallizes in the wurtzite structure and thus shows pyroelectric and piezoelectric properties enabling sensors, for instance, with sensitivity to normal and shear forces. TiN, on the hand, exhibits a high electrical conductivity. Moreover, the resistance of TiN against biocorrosion qualifies the material for applications in biogenic environments. One of the building blocks in MEMS processing is the ability to deposit thin films of material with a thickness anywhere between a few nanometres to about 100 micrometres. There are two types of processes, as follows. Physical vapor deposition consists of a process in which a material is removed from a target, chemical deposition techniques include chemical vapor deposition, in which a stream of source gas reacts on the substrate to grow the material desired
Proposal submitted to DARPA in 1986 first introducing the term "microelectromechanical systems"
Microelectromechanical systems chip, sometimes called "lab on a chip"