From MEMS to NEMS – the Ever Shrinking World
MEMs are built on the micrometer level and use semiconductor techniques such as 3D lithography to develop its features. The large surface area to volume ratio make surface effects such as electrostatics dominant compared to volume effects such as inertia or thermal mass. The Wikipedia definition provides more details.
An electromechanical system consists of two elements – a mechanical element and transducers. These have been existence for over 200 years. Mechanical devices measure vibration in response to an applied force. There are several kinds of devices including cantilevers, double-clamped beams, and torsion balance. Transducers convert mechanical energy into electrical or optical signals. For more details on electromechanical systems, check out this article.
Nanomechanical devices take this technique to an even smaller scale measuring even tinier vibrations reaching into the microwave arena with great sensitivity.
The Nano 50 Awards were recently announced. The list of winners indicates a technology emphasis on alternative energy and semiconductor techniques and a product emphasis on new materials.
Recent trends include improved sensitivity of sensors, advanced development of scanning probe microscopy and better high-frequency filters and switches in signal processing circuits.
UCLA recently created the Nano-valve which can hold and release molecules at will. Recent advances in carbon nanotubes make nano-switches possible. Applying electrical input deforms the nanotube in a predictable manner. This deformation coupled with careful positioning of the device can create a nano-switch. A more detailed explanation can be found here.
Virtual Instrumentation brings tools to the task of characterizing nanoparticles. Since quantum mechanical rules apply at the nanoscale, particles bond differently and thus must be characterized. For particles on the nanoscale, scanning tunneling microscopes and atomic force microscopes must be used. Nanomanipulators can be used to bring the electrical signal from the nanolevel out to a point that instrumentation can measure the current. Here’s an interesting nanohandling application using haptic interfaces.