A few things about MEMS devices I have not been able to figure out is:
1. Is the sensing/moving structure actually disconnected from the rest of the device?
2. If so, how does it not get stuck to a side?
3. If it isn't disconnected, doesn't the friction from the connection cause an offset in the reading?
4. How do they etch the structure so that it is disconnected from the layer below?
1. Not entirely, it has two degrees of freedom. Think of it like a bridge.
2. The opposing springs are normally in equilibrium, so in the absence of forces the center mass moves back to position zero.
3. Think of it like a bridge. The points of contact and support are to the sides and stationary, while the spring mass system is suspended in air or in a vacuum.
4. Is simple enough if you start with two disconnected layers of materials, and then etch the top layer. You could also start with a layer of something like photoresist spincoated on the bottom layer, except for the adhesion points...
An interesting real-life scenario was the possibility of helium atoms being able to get inside the MEMS clock of some smartphones and cause the phone to stop working until enough helium can escape.
I wonder why it's still here after all these years? It seems both useless and harmful, one of those features whose lifecycle consists of someone rolling it out because of some idea they had and then removing it three hours later after having to fix multiple headlines because they didn't think it through.
I don't have time to watch the video but I was curious why MEMS gyros were shaped thus. Apparently it is to maximize sensitivity through the Coriolis force.
2. The opposing springs are normally in equilibrium, so in the absence of forces the center mass moves back to position zero.
3. Think of it like a bridge. The points of contact and support are to the sides and stationary, while the spring mass system is suspended in air or in a vacuum.
4. Is simple enough if you start with two disconnected layers of materials, and then etch the top layer. You could also start with a layer of something like photoresist spincoated on the bottom layer, except for the adhesion points...
An interesting real-life scenario was the possibility of helium atoms being able to get inside the MEMS clock of some smartphones and cause the phone to stop working until enough helium can escape.
God, I so hate the auto-title "fixing" feature on HN.
What is it even supposed to do?
https://en.wikipedia.org/wiki/Vibrating_structure_gyroscope
Their peculiar geometry reminds me of computer-designed antenna.
https://en.wikipedia.org/wiki/Evolved_antenna