MEMS and NEOMS

Though Micro-Electro-Mechanical Systems (MEMS) are not actually part of the nanotechnology revolution, they will ultimately play a large role in its development.

MEMS takes the idea of the lithographic semiconductor process and puts an entirely new spin on it.  Lithography is used primarily as a way to pattern microchips with extremely fine detail.  In general: the finer the detail, the more complex the computing system, the faster the microchip.  But MEMS isn't about component density.  The goal behind MEMS is to create functioning electronic AND mechanical systems in the micrometer regime.  I'd like to put a heavy emphasis on the mechanical portion, as this is a crucial concept.

Making mechanical devices with micrometer features is not as simple as patterning a microchip with a 90 nm EUV litho progress.  It requires great precision and innovation to make a micro-array of fully addressable mirrors, for instance.  Big names like Texas Instruments have recently applied MEMS toward the field of optics.  They've created an array of fully tilting micro-mirrors that are now used in modern projectors.

Such a micro-mirror array requires a high level of integration between extremely small mechanical parts and their electronic controls.  Much of the work going into MEMS will pave the way for nanoscale applications, namely the field of nano-electro-optical-mechanical systems (NEOMS).

Consider the current micro-sensor.  It is a MEMS application that sports a cantilever that is only micrometers long.  This cantilever vibrates at a natural frequency dependent on its material and length.  The tip of the cantilever can be fictionalized to bond with a target molecule.  When that molecule lands on the tip and sticks, it changes the vibration frequency of the cantilever.  This change is detectable, and the entire device forms the modern biological sensor.  It's already been used to find a number of airborne agents like anthrax.

The micro-sensor idea serves as a good example because it could easily be transposed to a nanoscale version with even greater accuracy.  With smaller cantilever sizes, even the smallest molecules could be detected with ease.  Furthermore, all of the foundry work related to MEMS applications also finds use in NEOMS applications (they're not exactly the same though).

Though right now, MEMS is more advanced than the state of NEOMS, one day we'll begin to see a wide array of funky new devices that take advantage of tiny mechanical parts that are only nanometers in length.