The ingenious micro-mechanisms inside your phone 

🚨Correction! A paper about this exact mechanism has been shared with me: transducer-research-foundation.org/technical_digests/HiltonHead_2010/hh2010_0061.pdf The X/Y gyros had two plausible explanations, and I picked the wrong one 🤦‍♀ The general principles hold, but the drive and sense directions are flipped in the X/Y gyros. I.e. the drive direction is up/down, and sense is left/right in-plane. 🚨Correction! At 6:00 I misattributed some of forces involved. @StadtlerHM sent me this correction in private, but I thought it warranted being pinned so more folks could read it! > "So when you drop your device and there is a downwards acceleration, the frame of the mems device will move down, and because the [proof mass] is decoupled from the rest of [the frame], it will attempt to stay where it is by moving upwards." This is true for how the phone detects acceleration to the phone by any force that acts on the frame, but not the proof mass. Gravity however acts just as much on the frame as it does on the proof mass, and as such there will be no difference in acceleration from gravity between the frame and proof mass. An accelerometer therefore can not detect acceleration from gravity when accelerating when in freefall. Instead, when the phone is stationary, the proof mass will hang low, being pulled down by gravity, with the flexion joint pulling it upwards to keep it stationary. When the phone is dropped, the spring force remains, but the gravitational force now acts equally on the frame and proof mass, causing the accelerometer to detect no apparent acceleration from gravity. Because the spring force is pulling the proof mass upwards, it will be pushed upwards relative to the frame, causing it to appear to stay stationary, and "lag" behind the frame in the fall. In short, the reason the proof mass stays stationary is due to the force from the flexion joint, not because of inertia causing it to "move up". Both the phone frame and proof mass have inertia, and both are affected just as much by gravity. The spring force on the proof mass acts as a spring that's bent and released, accelerating it upwards and starting to oscillate. This is why your test shows the proof mass "lagging" behind the frame when first dropped, then subsequently starting to oscillate. Thanks @StadtlerHM!

Wow Zach, this is the next level in explainer videos. Absolutely fantastic! I think that making the models that you can actually take apart and interact with added a lot of educational value!

The quality here cannot be understated. I was already impressed just with the diagram, and then to make a *working* 3D print AND test and graph it just blew me away. A truly new standard of explanation.

Don't think for a minute that your subscribers aren't fully aware of just how much time and effort and work you're willing to put into a single episode. There aren't many RU-vid content providers that are willing to put the work into a single episode as you are so I just wanted to say thanks, it's impressive and much appreciated. You deserve far more subscribers than you currently have and I believe that if you continue to produce episodes of this quality, your subscriber numbers will grow pretty quickly. Thanks again.

Men will literally 3D print life sized MEMS devices instead of going to therapy

This is the best MEMs accel/gyro video I've seen

MEMS devices are amazing. I don't think people realise how many applications they have - from printers and projectors, to accelerometers and barometers. That's just a few possible applications. Also, Bambu Lab crew!

I am completely blown away by the quality of this episode (my first) and the fantastic models you made to illustrate something that has mystified me for many years. All my web searches over the years never turned up an explanation/demonstration that could help me understand how these devices work. Thanks so much for all the time and thought you obviously put into it. If there is an award for work like this it’s hard to imagine a more deserving creator.

This is totally fascinating! YES, the big models did help in showing how the mechanisms work. And the thing is, while in theory this is not that complicated - making all those 'tiny' sized components to detect all of this - I'm just blown away. Thank you!

silicon is extremely flexible when it is thinned. i once had a wafer that was overetched (to the point equipment could no longer handle the sharp edges). I suspect it was 40 microns thick(they start around 800 microns thick), but didn't get a measurement. It was 8" diameter wafer and was able to grab it and fold it in half so it was touching itself like a taco. it just flexed back to flat after. its hard to believe a single crystal could be so flexible but it also does teach a lesson about how stress works.

Modeling and printing the MEMS devices was absolutely brilliant and elevated this video to top tier. Well done, it was definitely worth the time spent making it in my opinion.

Increbile how such a small mechanism can be integrated in a ridiculously small chip giving precise result and with such a low cost! Absolutely brilliant video. Thank you for sharing! 😁

I'm an elementary STEM Lab teacher and I love your use of larger 3D printed models to explain how the accelerometers and gyroscopes work. Brilliant idea! And your explanation is equally easy to follow. Well done!!!

The amount of work you put into recreating and printing those is really appreciated it looks amazing

around 4:35, not just that they can do it, but how good they r at it, im still consistently blown away at how accurate n repeatable parts r

Okay, I have to say, I knew how MEMS devices work and accelerometers and gyroscopes and stuff. I've even seen the pictures of the internal structure. That being said.. Your level of detail and visualization is freakin AWESOME. Amazing job with every bit of this.

Outstanding! Many in the comments are pointing out "corrections" The fact that you modeled this so beautifully that understanding it is INTUITIVE for most everyone, and to the point where we can critique your every word with that deep understanding is... amazing. You can see it flexing and moving and it just makes sense. Wow.

Making a blow-up of the MEMS is a boss move! Thanks for putting so much effort in this awesome video

Absolutely excellent job explaining MEMS. You went to a lot of work building those models, worth the effort in my opinion.

Your generosity in sharing knowledge with complete strangers, for the love of science and learning, is what science in its purest form has always been about. Many thanks.

It's absolutely crazy to think we have sensors that are able to detect such small forces.

You seem to go above and beyond to help us understand things. I only recently came across your channel. I think RU-vid recommended one of your shorts. I watched it and then went flicking through your catalog of videos. It’s some reason good educational content and I love learning. Thanks 😊👍

Your physical models are incredibly helpful to understand what the devices are doing. I had no idea that a tuning fork can be the main part of a gyroscope. That is a huge advantage over the spinning wheels method for making it microscopic.

A+ on the effort alone. Everything else is just gravy

I just found this channel and WOW! The fact that you made physical models to explain these complex concepts and devices Absolutely amazing You are a true engineer and extremely effective teacher!

would love to see a DLP (projector) MEMS

This is an insane physical model! Thank you for taking the time to create it and explain it to us all

Hi Zack, I really am blown away with your approach, equipment, testing and explanations. And of course the crazy amount of time spent in tracing. I am glad that Gen had you tell me about your channel! Really fantastic! I passed on a link to your channel to a number of people.... Great work!

serious props for manually tracing out those mems, really helps seeing how they function with a model that can move instead of just still images

I've always wondered how this actually works on the microscopic level. No better person to learn from. Really appreciate your work and the calmly-grounded-yet-awe-inspiring way you present it. It's clear in each of your videos that untold hours of curiosity, experimentation, frustration, eurekas + filming and editing are behind the final product, so thank you for all you do. 👍

The quality of this video is incredible. I'm continually amazed by the level of education one can find for free on RU-vid. Thank you sir

"Delicate" is an understatement on a scale, where "understatement" is an understatement... These things are, to me at least, incomprehensible small. If I'm not mixing up the scales here, then some parts could be the size of fingernail width next to a tree trunk, where the tree trunk is a human hair... It's just insane. And fascinating how "normal" technology made it that these things are everywhere because they can be made THAT easily these days. Also a "Thank you

I'm not sure if you've done a video on one of the OG popular MEMS devices (DLP chips or inkjet printer nozzles) but they'd be neat to see and are structurally quite simple to understand. I'd also love to see more insight and models with some of the tiny motors and microfluidics devices they make using MEMS technology, although I know such devices are much more niche and hence harder to get a hold of than something commodity like an accelerometer/gyroscope. I know they also make MEMS microphones these days, so seeing how those are built and comparing them to the previous go-to for compact microphones (electret capsules) would be fascinating. They can also apparently make compasses (do they use an electromagnet? tiny permanent magnet?) and humidity sensors (what part of this is responding to humidity?) in MEMS, and I can't imagine how they're pulling that off so those might be neat to investigate as well.

Really appreciate the effort you put in to create those 3D prints! I've watched a few videos about these sorts of devices, and there's always a bit of handwaving about how they actually work. This was an amazing physical demo, I feel like I have a visceral understanding of how they work now.

It's hard to find very clear explanations on these devices, with real photos, and real models, and even test to explain very clearly a concept behind a device. Thanks man

My guy, this was one of the best explanations of computer stuff for a non computer person ever. Kudos.

Your video quality is beyond amazing. Super informative and helpful. As with a lot of technology i simply do not have time to read lots and lots on them, so videos like these provide months of research in 20 minutes or less, which is amazing. I do however need to ask, gravity is not a force, when you drop your phone, the ground is accelerating upwards and the phone will feel no gravity, according to GR. Therefore, does the phone have a range of pre set parameters for earths gravity, so it can detect the lack of acceleration?

I stumbled on this video while just looking for something to watch, and it caught my attention. I wasn't searching to learn about any of this but ended up learning far more than I expected to. I'm blown away by the work put into the 3D models and the easy to understand way it was all put. Amazing video!

Not sure if you have ever been a teacher, but the way you explain concepts (along with the amazing visual aids) make the information really digestible. Subbed, love the work you do !

Always excited to see a new Breaking Taps video!

Amazed at the work you've put into this. The gyroscope part was surprising .. literally had no idea that this was also a flexture and your explanation as to how it worked was excellent. So much high technology in phones.. incredible.

As hard as it still was to grasp the rought functionality of those devices. We can see it in completion. Makes you appreciate the sheer genius of the people who invented it and made it so unbelievable small.

Beautiful explanations, and beautiful models you 3d printed of these tiny mechanisms. I always casually thought about how these phones pick up on motion, position, etc. and guessed there had to be some moving parts somewhere, but never imagined how brilliantly ingenious and sophisticated the designs really were.

Having presented the accelerometer/gyroscope to my students last week, I actually had the idea if I could not make some simplified 3D-model. Now I linked your video in our course material and I will have a look at your 3D files later.

This is my first time in this channel. I am in awe about the attention to detail, what people can do with just a 3D printer. You got a admirer today.

When you drop your device, the sensor will detect that the acceleration upwards has stopped. It doesn’t detect an acceleration downwards. It becomes weightless, not sensing any acceleration. Until it hits the floor of course.

wowow what a wonderful demonstration. These are such cool and clever devices, and you nailed it. And huge props for taking apart real mems devices and sketching them into 3d prints! Thanks again!

This was a *phenomenal* video! I can imagine how tedious it must have been to trace all the elements, then convert them into a 3D model that could be printed 😮👍 That added SO much to the understanding, though, making for a really extraordinary explainer video. I found it especially interesting how they can integrate the Z axis into that same planar structure - I’d always wondered how they managed to do 3 axes, and thought there must be a second chip at right angles inside the package. This was also the first time I understood how they manage to translate the coriolis forces into a measurable signal. The shift in resonant frequency was entirely unexpected. A number of years ago I was looking at an application for a gyro where I needed a lot of sensitivity to small movements. Analog Devices (now part of someone larger, I think TI) had a unit that was an order of magnitude more sensitive than the standard parts. An engineer there explained that it operated on a somewhat different principle, but didn’t explain what that was. It’s be interesting to find out what that was :-) BTW, the killer app that made these jellybean parts was car airbags. They needed ultra-reliable inexpensive accelerometers, and the millions of units requirement drove the development of MEMS accelerometers. Gyros came later, once the basic tech had been perfected for the airbag market. Btw, what’s the purpose of the chip bonded on top? Just protection?

One of the best explanations I've ever heard of how a MEMS gyro/accel works. I had heard theoretical explanations of how they work, but nobody else actually made a physical model.

I'm less than halfway through, but this is so insanely interesting, and you put in so much careful work that I just have to subscribe right now. Insane video man, thank you for doing all that and sharing it with us!!!

Simply THE BEST explanation ever created!!! Seriously worthy of becoming most recommended / most linked to video on any platform. Thank you 🙏🏼 for ALL your time && effort!!!

This is absolutely beautiful. What a wonderful explanation! THANK YOU for gifting us all with this easy to access knowledge. It was, undoubtedly A LOT of work!

Amazing work. I wish all classes in engineering were like this. Models are important, but visually seeing it working on a scaled version and comparing it to the model is on another level.

Your 3D models are such a great tool to help understand what is going on. You have great methods to conveying how things work. I had no idea that these devices had any movable parts at all. Very eye opening for me.

Great video! Looking forward to see another MEMS device such as Microphone or Oscillator.

its so nice that you are totally crazy and you actually did all of this 🙂 keep them coming. best wishes

I'm mind blown at how well you explained all the mechanisms, even for a non-science student like myself to understand! Thank you so much, I hope you know we dearly appreciate all of your hard work!!

I gotta say, this was very enjoyable to watch. Most integrated circuit videos I have watched were quite lacking in actual information. I have worked with integrated circuits since the late 70's and was always amazed at how complex they became over the years. In the 80's we worked with Motorola 68000 CPU chips and had quite a lot of failures shipped to us. We were able to crack the tops off and look inside to see the cip itself. The mark one eyeball is not powerful enough to view the chip on its own and so we used high magnification. Under microscopes, the complexity was astounding. This was way back in the 80s....Its hard to imagine the complexity of today's cpu's with billions of transistors. Well done, and I look forward to more of your videos.

Awesome subject well explained ! It would be nice to see some early MEMS side by side with the best we have today and perhaps a glimpse into how they are made....cheers.

Wonderful video. I would love to see a part II of how MEMS are made, in particular the undercuts, using photolithography.

AS a 3D artist my I was Blown away by the Microscopic Art. Years ago they said it's impossible to see what's inside a MEMS device to which I was sad until Now. I was actually about to start modeling it from scratch using the images but Glad that you provided the 3D models. I would love to make a 3D explainer video if you want me to make one. Let me know thanks sir.

that moment when you traced and created a large model, wow, the sheer determination, thank you for the dedication and sharing this

This is an incredible presentation and explanation! Top 10 channels in my sub list and that's pretty big. I wonder if there are any MEMS devices which work in a piezo-electric way, where the flexure of the material produces a voltage and that is then converted to movements, vs this capacitance method.

Love these videos! Can definitely tell you're passionate about what you do

Absolutely fantastic! This is an amazing real-world view of bacteria-small comonponentry that we all just take for granted. Until now I had assumed that there were just dizzy pixies in my phone working out which way is up. Now I know! Thank you for making this and for going to the trouble of tracing, mapping and recreating this MEMS device as a 3D model.

That's really cool. I greatly appreciate your style of informing/teaching Zach. Thank you for your & everyone behind the scenes hard work bringing us the content. I look forward to the next notification from your channel 👍

Wow, I'm so happy to have been suggested this video!!! That is a mind blowing amount of work you put in to scan, take apart, trace and recreate the chip as a model. But it made for a great visual explanation, and I understand these devices so much more than I ever thought I would. They're both much more complex (in the intricate manufacturing) and more simple (basically just swiveling pieces) than I expected

This was extremely cool! Even though I had a basic grasp of how MEMS devices work, it was very insightful to see the 3D printed models and see the flexures bend. I love presentations that allow me to have a more intuitive understanding of various concepts, and this was definitely one of them. However, I didn't quite get how the change in oscillation in the gyros propagates to the measuring capacitors on the outside. Also, it would be great to see how the movements of the rest of the mechanisms are sensed. As for suggestions, a few years ago there was an interesting case of a MEMS resonator clocking an iPhone SoC that failed to operate when submerged in helium. DLP chips could be interesting to explore as well. I'm also curious how these devices are manufactured, but I'm not sure if this is within the scope of this channel. Thanks a lot for the video!

The macro scale models are *really* cool! Also, REALLY clever engineering! Never knew how accelerometers worked before. Ingenious! For me, It'd be really interesting to see a similar sort of model of how the touch sensitive displays work. Especially how to detect the proximity of a stylus without it actually touching the device.

Thanks so much for this video. As a mechanical engineer with a focus on materials science who works as a software engineer and whose dad is an electical engineer, MEMS devices are like the ultimate combination of my interests. This is such valuable information presented so clearly and simply

Awesome! We use LIS3DH accelerometers in our 3D printers (RRF) and I know that Klipper uses the ADXL345. It might be nice to compare those two as they are both used for the same purpose by different firmwares. It would be interesting to kickstart a debate about which one is better ;)

come here through recommendation of gareeb scientist

I am speechless! I watch a lot of RU-vid videos, seriously. Never seen this kind of piece. It's unique. So much effort in it. Thanks a lot.

Fascinating stuff, it takes a brilliant guy to understand the mechanism and made models to explain it. Imagine how smart those guys invented and made those instruments? Those guys are the unknown hero of the progress of civilization and humanity.

Wow! Thanks for the explanations. What amazes me is that such tiny 'moving parts' can be produced for ~$1 but remain reliable for years!

You got my upvote at 3:40, for tracing an entire MEMS chip into CAD so that you could CD print a human-scale model. Very awesome. The oscillation that you picked up isn't just in your 3D printed model. The real device is also going to have oscillatory modes, but these can be corrected for using software. Basically, you've got a fundamental signal, that's convolved with an impulse response curve that characterizes the device's oscillatory modes, yielding your observed measurements, so to go backwards, one can "deconvolve" the system's impulse response curve, producing an estimate of the true signal. The device maker probably knows the typical impulse response curve based on the device's design, but each device is going to vary slightly from the average, so if greater precision is desired, one could "calibrate" the device by more precisely estimating each individual device's impulse response curve. For example, a test harness could apply a specific acceleration pattern, and by comparing with the measured signal, the impulse response could be determined. Or it's also possible that the device can self-calibrate by observing typical motion. Or for such a small device, the oscillatory modes are probably at such a high-frequency that they can be eliminated by a simple low-pass filter. Tiny things tend to vibrate very quickly.

I just cannot believe we can make things like this that work so well and reliably for under a dollar. My jaw was on the floor this entire video

Sometimes I imagine a video like this being sent 50 years in the past. Scientists analyzing every word, every frame. Putting together a list of new ideas, things that still need to be discovered, while maybe being completely oblivious to the fact that the video was created by regular person and shared for free.

The instant Zac said "it took a week", I liked the video. Very informative, thank you for your work and dedication.

As an electronics engineering student, this is amazing it's given me more inspiration to continue with my studies !!

4:58 - In fact, the exact opposite of what you are saying here is true. The moment you drop the phone, it is in free fall, which means it stops feeling the gravitational field.

I used to build military UAVs. Never understood how solid state accelerometers worked in our avionics. The best explanation of solid state devices of have ever seen! 3d models over the top! Thanks man! Fantastic!

Wow, thanks for not only the explanation but all the VERY-HARD-WORK to make the 3D-print models. Very much appreciate your intellect and effort!

The best tech video I've seen in a good while. I don't even wanna think about how many hours are needed in CAD for the models. Great job!

I amazed at the kind of things people think up and invent. The level of Creativity and intelligence at that level really is amazing and should be appreciated. Thanks for all your effort. Reminds me of when i read the book how do it know that explains basically how computers work. A really simplified explanation of the core inner workings that anyone can understand without needing to know the complex theories and laws behind it

INSTANTLY pressed like & subscribe once it started playing how you modeled and 3D-printed the MEMs. Been watching a couple of your other videos too and they are absolutely incredible and informative!

Again again again! I wanna see more MEMS explained this way. This is awesome

Technically it remain mechanical because of how the movement it's done to get that information. I love the way you find to show us those principle! Thanks for this work!

Can we just appreciate how far technology has come? People have been complaining about the lack of flying cars or the shortcomings of certain technologies, but the stage we are at now would be unbelievable for those living 20 or 30 years ago. Just imagine having a component in your phone that is as small as a bacteria, it's mind-blowing. And how is it even manufactured? I find this truly intriguing and amazing!

The level of quality in this video is simply incredible.

The models you created are incredible. And I wouldn’t have understood the mechanism without them. Thank you for putting in so much work and sharing your understanding.

Extremely cool video! It's interesting that the Y accelerometer isn't just the X one rotated by 90 degrees. It seems clear that they wanted the gyros to have as much space as possible, and the space left for accelerometers ended up being rectangular, so they had to design two parts rather than rotating a square part.

This is insane that we as humans have designed something so small to work like it does on a microscopic scale. I am blown away with technological advances and creativity.

This video is completely amazing. I always wondered how they accomplished the seemingly magical task of fitting a gyroscope into a 2mm wafer. It borders on miraculous. Thank you so much for taking the time to explain these remarkable devices to us. It's really mind-blowing that these things work the way we do, and your explanation was equally mind-blowing. Again, thank you.

Great video! When you showed the microscope images I didn't think I could understand how the mechanisms move, but your printed models helped a ton. Crazy that these devices work accurately.

I think I may have just watched the best video I have ever seen on RU-vid!!! I feel that I can say that with 100% sincerity as well! This was just astounding work. I was half a second behind you when you said "what if I drew" it and then boom, 3d models and prints. Just amazing work! I am off to binge everything you have to offer! Thanks for all the work on this video.

Boy projected and 3D printed all elements to explain it better. What a sacrifice! Thank you.

Amazing that you printed giant AMs and Gyroscopes. So easy to understand when you see the Movement.

I could only imagine the amount of work u have put into this video. But now u have succeeded in getting me to understand how MEMS work. Well done!

This is one of the most interesting videos I have ever seen on RU-vid. It makes me wish I had studied electrical engineering in college. Thank you for putting so much time and effort into making this, wow!