Mistakes happen, but in a video about gyroscopes it's hard to forgive mistaking position and orientation. That's the kind of thing that warrants a delete and re-upload.
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?
I believe the answer to your question is that the structure is "connected" to form a solid piece of material, but like any real material it isn't perfectly rigid. So it can vibrate, kind of like a tuning fork, and the thinner parts can act as springs. See the diagrams here: https://pmc.ncbi.nlm.nih.gov/articles/PMC9571586/
If you wanted to use such a device as a simple oscillator, you just set it vibrating and measure the oscillation frequency. Since the material isn't perfectly elastic, the vibrations will eventually be damped and die out (I guess this is what you mean by "friction"), so you use a feedback mechanism to keep the oscillation going.
A gyroscope works the same way, except that you use feedback to maintain an oscillation in one axis, and measure how much of that oscillation couples to a different axis. Whatever effect the damping has on the final measurement, I would assume it can be easily calibrated out.
I don't really know how they physically manufacture these devices without damaging the tiny, delicate structures. It's kind of mindblowing that they're so incredibly cheap.
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.
A lot of clickbait titles start with "How..." and removing it was an attempt to make titles more neutral. Unfortunately it sometimes has nonsensical results.
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.
Mistakes happen, but in a video about gyroscopes it's hard to forgive mistaking position and orientation. That's the kind of thing that warrants a delete and re-upload.
It's an ESP32 with:
- microphone and speaker
- wifi
- bluetooth
- screen
- two buttons
- IMU with six dimensions
all for under $35.
You can see a video of me using it to control a web based mini plane simulator https://x.com/alexpotato/status/2109782226841870352?s=20
Wild how cheap this kind of stuff has gotten.
If you wanted to use such a device as a simple oscillator, you just set it vibrating and measure the oscillation frequency. Since the material isn't perfectly elastic, the vibrations will eventually be damped and die out (I guess this is what you mean by "friction"), so you use a feedback mechanism to keep the oscillation going.
A gyroscope works the same way, except that you use feedback to maintain an oscillation in one axis, and measure how much of that oscillation couples to a different axis. Whatever effect the damping has on the final measurement, I would assume it can be easily calibrated out.
I don't really know how they physically manufacture these devices without damaging the tiny, delicate structures. It's kind of mindblowing that they're so incredibly cheap.
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