MEMS technology

Which mems? There are lots of them.

Some MEMS oscillators stop oscillating when exposed to helium gas. They recover a few weeks later. There are other designs that are immune.

John

Then there are digital micromirror devices (DMDs) used for projectors, MEMS galvo scanners, diffractive MEMS add/drop couplers for telecoms, MEMS relays, and on and on.

Cheers

Phil Hobbs

Microphones and accelerometers too.

MEMS relays were very promising once, but were apparently unreliable.

Pity.

Yeah, the intersection of good MEMs metals and good contact metals turned out to be the null set. :(

Cheers

Phil Hobbs

Like reed relays. Clean metals cold-weld, and with low separation forces tend to stick.

Maybe that's another perversity of nature, good electrical contact materials stick.

Why not build in an unstick shaker?

mandag den 5. juli 2021 kl. 18.34.54 UTC+2 skrev Don Y:

I believe ultrasonic cleaning can damage or destroy some mems devices

That would make sense. But, aside from manufacturing, it would be hard to imagine a typical application domain where a "device" would typically be ultrasonic cleaned.

Maybe if you're making a sensor for auto-tuning ultrasonic cleaner drivers.

;-)

We have bought XOs (not mems) that have warnings against ultrasonic cleaning.

Does anyone use ultrasonic cleaning for electronics?

Stickiness doesn't argue against reed relays; you can unstick 'em by applying two N poles to the ends, and creating magnetic repulsion. It just depends on how you choose to drive them.

Oh, that's very practical when you have hundreds of them in remotely controlled instruments.

That said, in fact my experience with Elfein and Pickering reed switches has been excellent, with many switches having exceeded

500M operations without failures. Au contraire, the miniature Omron SPDT SMD relays have been miserable right from the start. The docs don't say you can't wash them.

Jeroen Belleman

We've used over 100K of the Fujitsu equivalent, regular and latching, and they have been fine. But don't water wash them either. Solvent is OK.

We're going all no-clean anyhow.

DPDT is cool. You can build matrix trees, range switches, flying capacitors, all sorts of stuff. See AoE3 p 360.

It was thought at one time that there might be an issue with flux residue becoming a little conductive at high temperatures. I don't know if that was ever proved, but for a while at least, ultrasonic cleaning was supposed to be the solution for repair work.

Yes, of course it is; it's how a reed would be configured for latching-relay use, with a suitable magnetizable armature.

Or, you could unstick one by hand with a couple of cow magnets, I suppose.

I had never come across the idea of feeding magnets to cows before. Feeding them to children seems to have caused a few deaths.

John

Been doing that with cows for years.

Plus you can stick them on your fuel lines and get 200 MPG. ;)

Cheers

Phil Hobbs

the issue is eating more than one and getting the intestine pinched between them