I think it is safe to say that MEMS (micro-electromechanical systems) has become a mature process/manufacturing technology. In the analog world, MEMS sensors (including microphones) have become mainstream, high-volume products used in cars, cellphones, game controllers, inkjet printers, and countless other applications. MEMS circuit elements are being used in various ways to replace quartz resonators, which have been unable to take advantage of the relentless shrinks available in microelectronic manufacturing (ironic, since quartz is also a silicon-based material).
From the early days when only a few brave souls at specialty manufacturing companies dared to try to make MEMS devices with any sort of yield, many foundries now offer MEMS processing. TSMC offers MEMS at the 180/150nm process node and is developing it at the 130/110nm node. STMicroelectronics offers multiple wafer fabrication and assembly sites.
So now that Micro is mature, it is inevitable that something smaller must emerge… and that something is NEMS (nano-electromechanical systems).
I read an interesting article the other day about researchers at Columbia University using a graphene NEMS device in an analog circuit. Graphene is a planar sheet of carbon atoms, one atom thick, often used in multilayer forms. It is claimed to be the strongest material known to man.
The researchers used a 2- to 4-micron long graphene device to build an FM radio transmitter, operating at about 100MHz, in the middle of the FM broadcast band. The graphene device is used as a VCO, driven by audio as a crude direct FM modulator. They recorded the transmission as received on a normal FM receiver: It is noisy, and the actual content is a rather annoying song – at least to my taste –but it demonstrated a use of a new material in an electronic system. The demonstration is obviously, and literally, science-project-level, and not really a ready-for-prime-time technology. But it’s a start.
Nanotechnology seems to be everywhere, and it’s something of a buzzword that is used somewhat liberally in everything from food additives and cosmetics to electronics. I’ve seen some interesting electronics applications of nanotechnology proposed. It turns out that carbon nanotubes are lightweight, strong, and very conductive at room temperature.
If the manufacturing cost can be reduced as production increases, the material can replace copper wires in lots of applications, from power transmission lines to airborne systems. Woven into a cloth, this stuff is great for lightweight, flexible, electromagnetic shielding. Some people are looking into using deposited carbon nanofilms for interconnect on ICs, since aluminum is becoming a problem.
I wonder if anyone out there is using any sort of nanotechnology to solve analog problems yet. Are you?
