New Resonator Technology

[THATguy]

http://phys.org/news/2009-08-tiny-mems-devices-filter-amplify.html

Might also be good for energy harvesting antenna's. Though they are extremely tiny components.
Fancinating though.

[Kleinstein]

The idea is not that new. It is done for at least 20 years - though the ones shown might be smaller than the ones I know. One initial idea was to use them as high Q filters - however this is today in many parts replaced by digital signal processing. Another use might be relatively stable (high Q) resonators - however to get a high Q and thus be a real alternative to a crystal, one would need vacuum.

I have used similar (though larger) micro-mechanical resonators at the university. In vacuum they can get a really high Q - in som cases comparable to crystals. I have measured values up to 1E6. However there is a higher temperature drift. I could imagine a few niche applications as a high Q tunable resonator and maybe as sensor. I build the right way and for the smaller high frequency ones, they are nor that sensitive to external vibrations - for the shown version it is more the measurement system that needs vibration insulation, not that resonator itself.

[T3sl4co1l]

There are "silicon oscillators" that claim to be MEMS, though it's unclear what structures they use (and how they're temperature compensated).  They are usually programmable, which seems to suggest there's a PLL and P/Q divider or DDS to generate the output.

Certainly, this approach gives better universality to an otherwise fairly fixed and narrow design (i.e., you can only make the MEMS elements so large before they're impractical, or so small before they're unusable).  They get better ROI, if not necessarily better performance as a result (if the PLL suffers from phase noise outside of the loop bandwidth, or if the DDS suffers from excess jitter).  That said, they're usually comparable to, or better than, cheap crystal oscillators.

I don't see MEMS filters offhand, though SAW could arguably be called a similar technology.  Mechanical filters (made from, I think, nickel or terfenol as transducer, and various mechanical resonator bits) had been common back in the day.

Tim