MEMs oscillator sensitivity to helium (helium kills iPhones)

Ғылым және технология

I tested the 32KHz MEMs oscillator used in some phones, and discovered that just a 2% helium environment will cause the oscillator to fail. I also do a teardown of the MEMs device, and inspect it under the electron microscope.
iFixit blog post: ifixit.org/blog/11986/iphones... and vid: • Does Helium Break iPho...
Original thread about MRI facility and iPhone failure on Reddit: / mri_disabled_every_ios...
MEMs silicon encapsulation: micromachine.stanford.edu/~bon... www.sitime.com/api/gated/AN20... sci-hub.tw/10.1109/TADVP.2003...
I added images and raw data here: drive.google.com/drive/folder...
Applied Science on Patreon: / appliedscience

Пікірлер: 1 200

  • @NurdRage
    @NurdRage5 жыл бұрын

    holy crap that's interesting.

  • @kevinbyrne4538

    @kevinbyrne4538

    5 жыл бұрын

    Hi, Nurdrage ! Didn't expect to see you wandering outside your lab. Weird phenomenon, eh?

  • @Adam-ru3km

    @Adam-ru3km

    4 жыл бұрын

    Why does helium diffuse into silicon while hydrogen does not?

  • @Adam-ru3km

    @Adam-ru3km

    4 жыл бұрын

    It's not concentraiting the helium; yet it's allowing it to diffuse, like the reactive non-medal is solivating a gas into it? Or is it slipping around imperfections in it's structure

  • @TheLightningStalker

    @TheLightningStalker

    4 жыл бұрын

    Ozone will also kill all kinds of semiconductors, including LEDs. I was using an ozone generator in a cabinet and it had an LED and microcontroller both die. The concentration probably has to be fairly high and it takes days or weeks to happen.

  • @rich1051414

    @rich1051414

    4 жыл бұрын

    @@TheLightningStalker Ozone is an oxidizer, so I am sure it will kill sensitive things, but by totally different means.

  • @johnnz4375
    @johnnz43755 жыл бұрын

    The ultimate punishment for teenagers, if they don’t behave put their phone in a bag of helium, and they can’t use their phone for 3 days...😂😂

  • @GRBtutorials

    @GRBtutorials

    5 жыл бұрын

    Except that would only work with iPhone 8 or later... And it'd probably cause more problems than would solve.

  • @JlerchTampa

    @JlerchTampa

    5 жыл бұрын

    Maybe we need to send mass shipments of helium balloons to all the Apple Stores?

  • @mbirth

    @mbirth

    5 жыл бұрын

    @@JlerchTampa Or empty a few bottles of Helium into some Apple warehouses …

  • @michaeldellacava

    @michaeldellacava

    5 жыл бұрын

    They couldn't put in a few drops of epoxy to isolate it?

  • @MrMissionkid

    @MrMissionkid

    5 жыл бұрын

    I wonder if there is any permanent damage even after the He has diffused back out of the device...

  • @TechIngredients
    @TechIngredients5 жыл бұрын

    Thanks, very interesting!

  • @lukedare-white3131

    @lukedare-white3131

    3 жыл бұрын

    Dudeeeee this is like a crossover event I never even realized happened! Love both of your guy's content.

  • @PeterShipley1

    @PeterShipley1

    2 жыл бұрын

    thank you for showing conclusions first and I presented the data as if it was a mystery novel.

  • @keeperofthegood
    @keeperofthegood5 жыл бұрын

    Look up the paper: Diffusion in Silicon Written by: Scotten W. Jones. In that it is stated that He has a constant of diffusion that is a lot higher than Hydrogen. From that paper, Helium diffusivity (constant of diffusion) is 0.11 cm^2/s, Hydrogen's constant is 9.4x10^-3 cm^2/s but there are other compounds listed and some (like S 0.92 cm^2/s) are much higher than He, it would be interesting to use a sealed chamber and hot plate and liberate some S into the environment of these chips and see what the failure process would be and if it is recoverable.

  • @tomewyrmdraconus837

    @tomewyrmdraconus837

    5 жыл бұрын

    My question is why? Helium is literally twice the size of hydrogen... how does it diffuse almost 100x faster?

  • @garymarsh23

    @garymarsh23

    5 жыл бұрын

    @@tomewyrmdraconus837 A H2 molecule is a lot larger than a He atom.

  • @Doping1234

    @Doping1234

    5 жыл бұрын

    @@garymarsh23 I doubt hydrogen diffuses through silicon as a dimer. I suppose the potential well of a H interstitial in a silicon lattice is just deeper than for He

  • @AdityaMehendale

    @AdityaMehendale

    5 жыл бұрын

    @@tomewyrmdraconus837 He_1(atomic) is smaller than H_2 (molecule) - the real question is - why would Sulphur diffuse so rapidly?

  • @toddchristenson632

    @toddchristenson632

    5 жыл бұрын

    need to consider those 'constants' more carefully - keep reading and see Fig. 1.23 - molecular hydrogen diffuses faster than helium in single crystal silicon, search for articles by Douglas Sparks for more insight into this issue

  • @Nighthawkinlight
    @Nighthawkinlight5 жыл бұрын

    The enclosed oscillator is some 100+ times larger in volume than the naked one. Why is that?

  • @AppliedScience

    @AppliedScience

    5 жыл бұрын

    That huge ceramic/metal package is actually a mems gyroscope, not an oscillator. I was just using it to show a true hermetic package. The manufacturer could have made it smaller, but it's an older device, and there wasn't as much market pressure on that product to make it tiny.

  • @cryptonein

    @cryptonein

    5 жыл бұрын

    @@AppliedScience remarkable work. Can you give us a rundown of your workshop / lab setup sometimes? It would be nice to work towards being able to get the kind of insight that you're able to work out in these videos. Having a "shopping list" (or more realistically, a wish list) would be amazing to have as guidance.

  • @doctorbobstone
    @doctorbobstone5 жыл бұрын

    An interesting idea to try would be to see if you can restart the oscillator after exposing it to helium, but before it has stopped on its own. The way your test works, you have it oscillating and then you introduce helium. So, it is already oscillating as the helium concentration increases. However, it is possible that it takes more helium to "kill" it than it does to prevent it from starting. Normal oscillators are like that with cold. If take a running computer and drop the ambient temperature at some point it will stop running (0 C, -20 C, -40 C, whatever, it depends on the computer and the components they used to make it). But before that point, if you were to turn it off and back on it would fail to start. Maybe it's the same with the helium. That would explain why it takes days for it to recover. If you were to turn the oscillator on and off as it sits in helium, I bet there's a decent chance that it would fail to start sooner, but it would also recover sooner after that point because less helium has been absorbed.

  • @AppliedScience

    @AppliedScience

    5 жыл бұрын

    Yes. Power-cycling during the He exposure is a great idea!

  • @JasperJanssen

    @JasperJanssen

    5 жыл бұрын

    Under normal circumstances though, these oscillators are essentially never off in the devices. They might be powered down once you run your battery down to 0 in you iPhone, but that rarely happens.

  • @MattOGormanSmith

    @MattOGormanSmith

    5 жыл бұрын

    I had a car like that :)

  • @doctorbobstone

    @doctorbobstone

    5 жыл бұрын

    @@JasperJanssen That's probably true for the 32.768 kHz oscillator on a phone or watch as it is used for the RTC (real time clock). I still think that power cycling it would be informative, though. And on embedded systems which do not need an RTC, one generally only keeps the current oscillator on, so even the 32.768 kHz oscillator will be turned on and off to save power as the device switches to different modes, so again, interesting to test.

  • @monad_tcp

    @monad_tcp

    5 жыл бұрын

    Embedded systems can use an small RC resonant oscillator instead of the quarts to save power, but it's much less precise. Modern CPU are too complex and timing is too strict for them to do that, they can't change de PLL that easily while running (they can change the multiplier though, to save power).

  • @xmotomitchx4213
    @xmotomitchx42135 жыл бұрын

    Interesting! I work in the semiconductor industry, and we use helium to leak check systems under a vacuum. Good to know!

  • @tomewyrmdraconus837

    @tomewyrmdraconus837

    5 жыл бұрын

    You can probably check to see what oscillator your phone uses, but unless it's an iPhone 8 (or newer), you're probably safe.

  • @sauercrowder

    @sauercrowder

    Жыл бұрын

    Yes and btw, have to be careful about permeation when doing that since it will pass through o-rings etc. and indicate a false leak!

  • @arfink
    @arfink5 жыл бұрын

    Something else to consider is that many gasses can bond to surfaces that are very clean and free of oxide. I work with high vacuum systems daily and we have problems with both helium and nitrogen bonding to the tiny wires inside our ion pumps. Usually the solution to accelerating the escape of these molecules is to heat the grid up to a very toasty 300C or so for 8 hours while constantly pumping with the turbopump. On our leak detectors we sadly do not have a way to do this, so if they become poisoned with large amounts of helium it can take days to get them to stabilize.

  • @absurdengineering

    @absurdengineering

    4 жыл бұрын

    arfink Are you sure it’s surface bonding? Sounds like simple diffusion to me, if the oxides would form a diffusion barrier (I don’t know whether they in fact do, though).

  • @alterhec

    @alterhec

    Жыл бұрын

    Fragilization/embrittlement of metals (or metaloids) by H2 (or He...) induces the structural failure (SF) of the monocrystaline quartz, hence the KIA of the mem. That SF is derived from multiple dislocations (and even early microcrack developments) while in service, wich ultimately act as difussional barries during the postmortem offgassing tests. In fact, offgassing timing is an interesting way of assessing the degree of dislocation networking without resorting to TEM

  • @joelmanthis9523

    @joelmanthis9523

    3 күн бұрын

    ​@@alterhec if I follow correctly, does this mean it's possible that even the tiniest fissure (crevasse) in a material, especially an alloyed metal; would inhibit diffusion of substancially smaller particles (like elemental He) and possibly even reflect them just like how snow (transparent H2O in solid form but it looks white because of the nucleation of ice secretion) will reflect light since photons are astronomically smaller particles? Probably not the best metaphor but if you disregard the effects of Ionization, Electromagnetism, Radiopacity, etc. maybe it can be a simple model to explain the phenomenon we see with Helium. I am fascinated by this because of the implications it has on superconductivity and everything that was learned in the early days of cryogenic when using Helium to develop what was called a "quantum fluid", just thinking about how electrical conductivity is totally different at incredibly cold temperatures and how wave propagation through a material is seemingly out of this world, nonetheless diffusion of a particle being mind boggling.

  • @thelamb288
    @thelamb2885 жыл бұрын

    I love the in depth details that you give. On many occasions they go over my head but I managed to stay with you on this one. Really fascinating production method. Cheers.

  • @evilcanofdrpepper
    @evilcanofdrpepper5 жыл бұрын

    Every time I see an Applied Science video in my feed I get excited because there is a 90% chance that I'm about to see something super awesome!

  • @MrMilarepa108

    @MrMilarepa108

    4 жыл бұрын

    100%

  • @imikla
    @imikla5 жыл бұрын

    That was outstanding detective work! You always inspire me to make better use of the things I already have, and tackle projects I thought were beyond my resources!

  • @ericthornton5763
    @ericthornton57635 жыл бұрын

    "At least its kpa" lol

  • @gordonwedman3179

    @gordonwedman3179

    5 жыл бұрын

    None of that rubbish PSI...

  • @GRBtutorials

    @GRBtutorials

    5 жыл бұрын

    @@invendelirium I doubt it as he says "strange units".

  • @Seaprimate

    @Seaprimate

    4 жыл бұрын

    could have been cm of h2o

  • @hyzercreek

    @hyzercreek

    4 жыл бұрын

    kilo pascals

  • @petercarioscia9189

    @petercarioscia9189

    3 жыл бұрын

    @@gordonwedman3179 imperial>metric

  • @RileySantiago
    @RileySantiago5 жыл бұрын

    The technology used in these chips is incredible, and those electron microscope images are beautiful! Well done sir!

  • @AxGxP
    @AxGxP5 жыл бұрын

    Wow! Very interesting. Thank you for this information and your investigations.

  • @stevepence9869

    @stevepence9869

    5 жыл бұрын

    Have something you might want to research. Health effects of microwaves at 5 gigahertz. How juxtaposition effects cells and body.

  • @AxGxP

    @AxGxP

    5 жыл бұрын

    ​@@stevepence9869 it's depends on power and distance from the source. Are you interesting wifi or military radars?

  • @stevepence9869

    @stevepence9869

    5 жыл бұрын

    @@AxGxP WiFi.

  • @bonniecrystal903
    @bonniecrystal9035 жыл бұрын

    Fascinating! Thank you for the wonderful inside look at the MEMs oscillator and especially the SEM views of the tuning forks. Your drawing also was quite marvelous.

  • @pyromen321
    @pyromen3215 жыл бұрын

    I saw your tweet about this a while back, but I had no idea you were working on a video about it! Awesome!

  • @thejesuschrist
    @thejesuschrist5 жыл бұрын

    Fascinating! Thanks for enlightening me. Science is the best!

  • @kie9683

    @kie9683

    3 жыл бұрын

    Omg Jesus hellos 👋

  • @DynoRC

    @DynoRC

    3 жыл бұрын

    Achievement unlocked Jesus enlightened

  • @turolretar

    @turolretar

    2 жыл бұрын

    @@deanthemachine96 bruh

  • @Micah561
    @Micah5615 жыл бұрын

    the geometry of that mems is blowing my mind. Is there anyway to view the electron microscope images in higher resolution?

  • @AppliedScience

    @AppliedScience

    5 жыл бұрын

    I updated the description with a Google Drive link: drive.google.com/drive/folders/1l3mJ4UTs8aY70scH7vDaf0M8pLeP2kqI?usp=sharing

  • @Micah561

    @Micah561

    5 жыл бұрын

    @@AppliedScience thanks!

  • @SuperSiggiboy

    @SuperSiggiboy

    5 жыл бұрын

    Thanks for the pictures and your excellent experiments and commentary, Ben! It almost looks like some kind of space ship straight out of a sci-fi novel

  • @spankeyfish

    @spankeyfish

    5 жыл бұрын

    @@Micah561 Try shouting "Magnify!" at your screen.

  • @buddyclem7328

    @buddyclem7328

    5 жыл бұрын

    @@spankeyfish *COMPUTER!* (bleep) Magnify image. (bleep) Enhance quality. (bleep)

  • @ErikWooldridge
    @ErikWooldridge5 жыл бұрын

    This is probably the best coverage/video I've seen on this topic. Thanks for the upload!

  • @yachalupson
    @yachalupson4 жыл бұрын

    What an awesome tear-down/investigation! Love the level of detail, ego-less inquiry & yet in language that most people can understand. Thanks so much.

  • @michaelkaliski7651
    @michaelkaliski76515 жыл бұрын

    A stunning bit of work and hearty congratulations. Helium does leak through any and every containment vessel, so this all makes perfect sense. The timing difference between a device becoming disabled and reactivated by Helium diffussion is almost certainly due to differential vapour pressure. Initially there are billions of Helium atoms trying to diffuse into the MEMS device. However it only takes a few million molecules to stop the device working. When the external Helium atmosphere is removed, there are only a few million atoms to diffuse out, so much less impetus propelling the Helium molecules back out from the MEMs into the atmosphere. The Silicon containment provides sufficient protection from a vacuum to prevent that from speeding up the recovery process on its own. Perhaps the application of moderate heating combined with a vacuum might speed up the process slightly.

  • @marshalcraft

    @marshalcraft

    4 жыл бұрын

    this kind of suggest the helium is never bonded, a part of the Si crystal structure. Then the only real force forHe to leave is random motion of the He? What if you shake the device rapidly i wonder if it leave faster?

  • @taitjones6310

    @taitjones6310

    4 жыл бұрын

    @@marshalcraft no, Michael Kaliski is spot on with his explaination. Think of the Helium diffusing out of the device the same way you would if you flipped a full water bottle upside down, it would just glug, glug, glug. The difference in this case is that Helium is lighter than air, so it's only going to diffuse (glug) out the top of the device, but unlike the water bottle, there is nothing that can be exchanged in the vacuum. Maybe a better way of explaining this is putting your finger on the end of a straw an pulling it out of the glass. The vacuum will hold the liquid in, but not indefinitely.

  • @modelllichtsysteme
    @modelllichtsysteme4 жыл бұрын

    128 MEMs-engineers and some from apple disliked this video for sure! Thank you Applied Science for this really informative and interesting video! :)

  • @djmips

    @djmips

    3 жыл бұрын

    when you see this ratio your have to realize that a good portion of thumbs downs are accidental.

  • @andrewhamop6665

    @andrewhamop6665

    2 жыл бұрын

    Would be nice to see the dislike counts, but KZread just rolled out the removal to all videos...

  • @misoup1
    @misoup15 жыл бұрын

    I was just reading up on this today and I really appreciate the more in depth analysis you provided!

  • @Redafto
    @Redafto5 жыл бұрын

    I think i have subscribed over 50 channels, but you are my most favorite one! Just love how casual you investigate the most scientific topics.

  • @vejymonsta3006
    @vejymonsta30065 жыл бұрын

    What a strange failure scenario. Now I can go around and tell people not to put their iphone in helium, so I can explain this surprisingly complicated component failure.

  • @w2aew
    @w2aew5 жыл бұрын

    Fascinating Ben!

  • @MrRdubya
    @MrRdubya5 жыл бұрын

    Man this is super interesting! Keep these up! My jaw just drops at the ingenuity of these tiny micro devices. I would love to see more videos explaining this kind of thing.

  • @bpark10001
    @bpark100015 жыл бұрын

    There is no mystery for the slow recovery! I would assume only millitorr of He in the device will kill it. So with 2% He outside (15 torr), the difference driving the diffusion is 15 - .001 ~ 15 torr. Now we have the device filled to more then .001 torr (and it has failed). Now we put it in essentially 0 torr atmosphere, and the diffusion driving the He out is only 0.001 torr! No wonder recovery is so slow! (Perhaps it is not so extreme, as I assumed only 1 millitorr failure pressure). I am familiar with this process as I used it to refill old HeNe laser tubes. Glass (especially pure quartz laser windows) is a "sieve" for helium. Operating He pressure for the tubes is about 1 torr (Ne 0.1 torr). I used 0.1 atmosphere He partial pressure outside the tube to do the refill; it takes several weeks. (I use low pressure to slow the fill, and avoid arc-over outside the tube when testing). If you overshoot, you must wait years for He pressure inside to reduce! Most quartz crystals will work in 1 atmosphere. This oscillator technology must be very marginal to fail at such low pressures! This is miniaturization gone too far! I'll take the big can!

  • @ChrisGJohnson

    @ChrisGJohnson

    5 жыл бұрын

    This seems plausible, but is it consistent with the 1kPa environment not causing failure of the device? Perhaps it would have failed at 1kPa but it takes longer than the 24 minutes test shown?

  • @GRBtutorials

    @GRBtutorials

    5 жыл бұрын

    Yeah, you don't really gain that much space with that MEMS oscillator.

  • @tomewyrmdraconus837

    @tomewyrmdraconus837

    5 жыл бұрын

    @@GRBtutorials you should see the difference on an actual phone board. Also strongly affects the thickness of the board. Still agree that a failure mode that easy to encounter (not common, easy. There is a difference :-p) should be avoided for the cost of miniaturizing two components on a board with thousands. Imagine filling helium balloons and having your phone die for 3 days... that's just silly.

  • @AdityaMehendale

    @AdityaMehendale

    5 жыл бұрын

    But why the failure in the first place? Does the diffused helium reduce the Q-factor of the resonant-H oscillator? (i.e. it contaminates the vacuum inside the MEMS?)

  • @bpark10001

    @bpark10001

    5 жыл бұрын

    @@ChrisGJohnson It is inconceivable to me that any gas even at 1 atm should kill an oscillation. Perhaps because it is so small that surface to volume ratio so large that any gas will damp it too much. More likely the coupling is so feeble (electric field attraction only) and the desire to save power, they made the drive marginal. (I'll be willing to bet they they used @#$3.3 volts when they should have used 5.) Normally with such close clearance structures, even high gas pressure "looks like a vacuum" because there are so few molecules present in the gap. But this must not be the case. I wonder if MEMS gyros have the same problem?

  • @theroboticscodedepot7736
    @theroboticscodedepot77365 жыл бұрын

    WOW, that's really amazing! I had no idea manufacturing could be that precise. I'm really blown away.

  • @sasjadevries
    @sasjadevries5 жыл бұрын

    So simple, yet so complicated. So much effort has been made for a device that does so little (just vibrate). The funny thing is that digital electronics can't live without that one mechanical component.

  • @inductorbackemf7204

    @inductorbackemf7204

    5 жыл бұрын

    Nope,you have R C timing circuits have been done for almost the dawn of electronics. A crystal oscillator/MEMS is just a better way most of the time. Due to being much more stable.

  • @peetiegonzalez1845
    @peetiegonzalez18455 жыл бұрын

    What a great detailed look. I'm not a regular viewer but why do you have such an amazingly well tooled lab? Let's not mention your skill in putting the tests all together.

  • @nohandle1
    @nohandle15 жыл бұрын

    Fascinating! Thank you taking the time to investigate and share this :) subscribed!

  • @24680kong
    @24680kong5 жыл бұрын

    It would be interesting to see if you could open up a small hole in the MEMs chip so that hydrogen didn't have to just rely on permeation to get in. Then you could see if it still affects the oscillation. You could then determine if it's just the slow permeation that makes hydrogen unable to kill the iphone or if it also can't get into the oscillator to cause the crash.

  • @alexanderdaum8053

    @alexanderdaum8053

    5 жыл бұрын

    If you open a small hole in the MEMS, you probably will get Air in it too, which on its own would probably enough to kill the oscillator

  • @snaplash

    @snaplash

    5 жыл бұрын

    With a hole, the air and any HE could be cleared with vacuum. If it recovers immediately after vacuum is applied, then it's presence around the fork is restricting it's motion. If not, then the problem is the HE diffusing into the fork itself, and changing it's characteristics. It would be difficult though. Drill/grind, it stops, and you don't know if it's because you cut into the working bits, or if you let the air in.

  • @undysmorphic5928

    @undysmorphic5928

    4 жыл бұрын

    @@snaplash If you had access to the right kind of SEM microscope with FIB / GIS attachments it should be possible to do the required machining. Probably not simple, but almost certainly achievable. You can do some crazy things with those technologies! Look at the last "slides" of this PDF for some samples home.iitk.ac.in/~vkjain/L3-IBM-ME698.pdf

  • @Sam_596
    @Sam_5963 жыл бұрын

    "HF vapor" * shudders *

  • @SamZeloof
    @SamZeloof5 жыл бұрын

    beautifully simple and precise explanations, as always :)

  • @zetacon4
    @zetacon45 жыл бұрын

    Excellent work! I find your experiment brilliantly done. Reminds me of the engineering classes in college. We had a great time examining circuits under Electron Microscopes. Even the study of how circuit forming was done in the manufacturing process was amazing. Thank you.

  • @clifffarion7448
    @clifffarion74485 жыл бұрын

    Thank you, your article generates some thought . From my past- Implantable Heart Pacemakers are a complex electronic device with all their sensing, programmable and telemetry. I am probably safe to say they must contain a few oscillators. Unless the process has changed greatly since I left it. What you may not know is they are baked out in a vacuum chamber followed by back filling with helium, then they are sealed in the helium dry box and then passed through an anti chamber . The next step process is they are checked in a mass spec leak detector tuned to helium, if helium shows, they are leakers. We calibrated the detector with a calibrated leak which was rated at what we told guests, was around 1cc that would take 3000 years to leak out . (Testing my memory I think the numbers were 1.6 to 10 minus 16 standard cc per second, I left there 30 years ago )

  • @olik136
    @olik1365 жыл бұрын

    that oscilloscope is twice as big as my future

  • @realedna

    @realedna

    5 жыл бұрын

    ...also twice as bright!

  • @spehropefhany

    @spehropefhany

    5 жыл бұрын

    @@realedna Danged millennials, walking around like they rent the place.

  • @snaplash

    @snaplash

    4 жыл бұрын

    And less than half the weight of my 100Mhz analog scope.. (A bit more expensive though.. )

  • @GarrettFogerlie
    @GarrettFogerlie4 жыл бұрын

    You’re videos are so awesome! Thank you so much for the amazing tests and details!!!

  • @ErrantLight
    @ErrantLight5 жыл бұрын

    Thank you for the thoughtful and rigorous experimentation. Love that your inquisitiveness led to an answer we can all appreciate!

  • @electronicsNmore
    @electronicsNmore5 жыл бұрын

    Another great video!

  • @TheCarmacon
    @TheCarmacon5 жыл бұрын

    MEMS engineer here. Leaving vents in the silicon cover for HF to pass through? I doubt that, do you have a source? Instead, I wouldn't bother growing those oxide layers and simply bond a second Si wafer on top of everything, plain and simple. For resonance applications one does not simply grow oxide on a large scale and then etch it away. That results in way too much and hard to control deviations in the oscillating masses. With the HF in the cavities you'd get a lot of condensation of the reaction products. They can also detach and shift during operation, thus randomly changing the characteristics of the sensor.

  • @ericward7996

    @ericward7996

    5 жыл бұрын

    Correct, MEMS oscillators are usually capped with a silicon wafer; however, interestingly this does not prevent helium permeation, see Output Drifting of Vacuum Packaged MEMS Sensors Due to Room Temperature Helium Exposure, Journal of Sensor Technology Vol.3 No.4(2013) (freely available).

  • @2342cheese

    @2342cheese

    5 жыл бұрын

    @TheCarmacon not BOE/Liquid HF, Vapor HF a bunch of companies make the tools now for a oxide release layer similar to XeF2 etchers with a poly release. It is typically a Vaporized HF mixed with Ethanol as a carrier allowing ionization to occur and thus etching of the oxide. I think the switch from bulk to surface MEMS processing largely contributed to the development of the vapor HF process. There's a few other inconsistencies(to the paper) in his evaluation of the process flow. They start with a SOI wafer, pattern that then do a oxide fill. They pattern the oxide then do a poly hardmask, the hardmask is then patterned with a series of holes protecting the electrodes and the center of the oscillator giving it a fixed point to hold in place. The HF vapor ignores the thin poly but eats the oxide freeing the proof mass. I would then assume that they do PECVD poly as they're depositing 20um on top, also in the PECVD process the cavity would be pulled to vacuum as well as having the wafer heated to around 400C or so. So if you have a staging step to bring the wafer to temp any condensation should be alleviated and form the seal to the cavity. If the holes are small enough they'll close due to gap-filling besides being hammered with 20um on top of it. This sort of proof-mass release process is not unique with poly-based structures for surface MEMS processes anymore. I certainly see where you're coming from if they started with a bare wafer and not a SOI wafer though it would be obnoxious.

  • @marshalcraft

    @marshalcraft

    4 жыл бұрын

    total bullshit

  • @proskub5039
    @proskub50395 жыл бұрын

    The bit about the manufacture of a cavity inside the silicon also explains how MEMS pressure sensors are made! These things are pretty amazing - due to the stability and elasticity of the silicon cavity they can respond to pressure variations of 1/1000000 of full scale. I've personally used a 1000 bar pressure sensor as a barometer.

  • @andynz7
    @andynz75 жыл бұрын

    The quality of your videos is just incredible!

  • @Patchnote2.0
    @Patchnote2.05 жыл бұрын

    One of my favorite videos of yours. Every video is such a treat!

  • @KohuGaly
    @KohuGaly5 жыл бұрын

    What is it exactly that kills the device? Is it the helium atmosphere inside the device causing friction and viscosity and thus damping and down-tuning the oscillator? Or does the helium conduct electricity and discharges the electrodes that that should electro-statically drive the fork? BTW, the reason why there are 4 tuning forks is simple - to keep the centre of mass in single spot. When you have singe fork [ I ] , the centre of mass swings with it. When you have two [ U ] you fix the center of mass horizontally (the arms swing in and out), but there is still motion vertically (each fork moves out and down, then in and up, in and down, out and up, ...). When you put 4 forks [ X ] their vertical movement cancels out and the centre of mass stays put. The result is, that the device does not leak energy via vibrations and is less sensitive to outside vibrations.

  • @Abdega

    @Abdega

    5 жыл бұрын

    I’d guess its because the penetrating helium is causing strain on the silicon and making its oscillations change?

  • @KohuGaly

    @KohuGaly

    5 жыл бұрын

    you mean like, the presence of helium atoms in the crystal lattice changes the hardness/flexibility of the silicon?

  • @VicVlasenko

    @VicVlasenko

    5 жыл бұрын

    KohuGaly or it's just friction between "moving" parts and helium

  • @praveenb9048

    @praveenb9048

    5 жыл бұрын

    It may also have something to do with the Reynolds number at that small scale. The effective viscosity would be really high. I saw a KZread video where they explained how really small animals actually swim rather than fly through air. To them, air could feel like honey.

  • @AaronALAI
    @AaronALAI5 жыл бұрын

    Great video! I recall seeing the first Reddit post about this and subsequent posts regarding helium influence. It was hard for me to believe at the time also, but the emp hypothesis was much harder to believe. Do you think other mems type sensors could be influenced. Maybe angular rate sensors or accelerometers? I think angular rate mem sensors utilize a similar resonance tuning fork setup as described in your video.

  • @IanGrams
    @IanGrams5 жыл бұрын

    Oh hot dang I just learned about the iphone sensitivity to helium a few days ago. Looking forward to learning about it all in depth. Thanks Ben!

  • @insightfool
    @insightfool5 жыл бұрын

    Using your SEM for the benefit of other nerds. Love it! Thanks.

  • @davidberndt6275
    @davidberndt62755 жыл бұрын

    MicroElectroMechanical --- Thanks Ben!

  • @thisnicklldo
    @thisnicklldo5 жыл бұрын

    Outstanding. Both your home shop science and the analysis of the underlying technology. Thank you.

  • @GarageScience
    @GarageScience5 жыл бұрын

    I learn something new every time I watch one of your videos. Thanks for the quality content!!!

  • @vitorhearteater
    @vitorhearteater5 жыл бұрын

    Amazing video. Very interesting. I was imagining if you could do the same with the acelerometer IC, as it is also a MEMS. Would it have similar results?

  • @askquestionstrythings

    @askquestionstrythings

    5 жыл бұрын

    My understanding is all mems devices are susceptible to helium exposure, but exposure to levels of helium that cause problems are not common.

  • @Bright8888

    @Bright8888

    5 жыл бұрын

    @Ask Questions, Try It - Apart from exposure levels, an important factor to be considered is whether the silicon of MEMS is hermetically sealed or open to gases in the atmosphere. In the case of iPhone 8 and later models, due to space constraint, the MEMS is made extremely small and is not sealed. So, if the MEMS device, - whether it is an oscillator or an accelerometer - is hermetically sealed, it will not be susceptible to helium exposure.

  • @wangyeeee
    @wangyeeee5 жыл бұрын

    nice vid! I'm curious to know what would happen to other MEMS devices used in a smart phone such as microphone, accelerometer and gyroscope(not the ADI one at 4:12).

  • @alexholker1309

    @alexholker1309

    5 жыл бұрын

    I was wondering the same thing. Does a MEMs accelerometer under constant force vibrate or is it stationary? If the former, I assume it would suffer the same problem. If the latter, it might be operating at such a low frequency that the helium has no significant effect.

  • @PiotrEsdenTempski
    @PiotrEsdenTempski5 жыл бұрын

    That was fascinating! Thank you for putting all this information and experiments together! :D

  • @robgandy4550
    @robgandy45505 жыл бұрын

    Wow dude, you did it again. Very cool. And I'm glad you got your electron microscope working properly. Thanks,.

  • @jaredj631
    @jaredj6315 жыл бұрын

    I should be carful when welding stainless steel. I used 93% helium as and “active gas” to increase the heat on a mig welder.

  • @GRBtutorials

    @GRBtutorials

    5 жыл бұрын

    Carful? You mean "as much or as many as a car will hold"?

  • @buddyclem7328

    @buddyclem7328

    5 жыл бұрын

    @@GRBtutorials Good eye! I can't believe that slipped past my spelling detector.

  • @buddyclem7328

    @buddyclem7328

    5 жыл бұрын

    Electric welding would be enough to fry any mobile device. I avoid having any mobile device near anything I am working on, since they can easily break. My grandfather wore his watch on the inside of his wrist to avoid breakage, and I never wore one at all when working, keeping a dollar store watch in my pants pocket.

  • @bruhdabones
    @bruhdabones4 жыл бұрын

    Me: *puts friend’s iPhone in bag and pops balloon into it* Friend: Ha! I know what you’re doing - it won’t float! Me: Oh, you just wait >:)

  • @thecrow9337
    @thecrow93375 жыл бұрын

    Your videos are Always fun to Watch and Very interesting! Keep up that great Work :)

  • @RETRODISTORT
    @RETRODISTORT5 жыл бұрын

    This video just made me appreciate electronics and chemistry much more. I'm so exited, great contribution!

  • @KerryWongBlog
    @KerryWongBlog5 жыл бұрын

    Very informative. So this means that these MEM oscillators are also sensitive to alpha radiation as the radiation produces helium. Would be interesting to see how these MEM oscs handle in a radioactive environment.

  • @gordonwedman3179

    @gordonwedman3179

    5 жыл бұрын

    I think alpha radiation consists of a helium nucleus. I do not believe alpha radiation creates helium.

  • @MCSteve_

    @MCSteve_

    5 жыл бұрын

    @@gordonwedman3179 You're right but it's still Helium, since it's number of protons don't change. Alpha Radiation is just a Helium cation.

  • @24680kong

    @24680kong

    5 жыл бұрын

    Alpha particles don't really penetrate anything, so they'd strike the outside surface, gain 2 electrons, and act like regular helium (unless it reacts with the silicon nucleus). So It would probably act just like regular helium.

  • @gordonwedman3179

    @gordonwedman3179

    5 жыл бұрын

    I would think you would need to have a very high alpha radiation level to give the same number of nuclei as present in two percent helium gas but I imagine at some point the effect would be the same.

  • @bpark10001

    @bpark10001

    5 жыл бұрын

    @@gordonwedman3179 Yes it does! As soon as the alpha particle is slowed down, it grabs up 2 electrons to make a complete helium atom. This same effect causes containers with strong alpha emitters to eventually burst because of the accumulated He gas. But alpha particles would mostly be stopped before getting in.

  • @nnamrehck
    @nnamrehck5 жыл бұрын

    It is typical in chemical processes that sorption is fast while desorption is slow. Often this difference is due to a chemical interaction between the substrate and absorbed species.

  • @absurdengineering

    @absurdengineering

    4 жыл бұрын

    Damn Yankee That’s a different mechanism. Here it has not much to do with substrate interaction, but with partial pressure gradients across the diffusion membrane. It’s easy to produce almost arbitrarily high gradient from outside in, but going inside out, the best you can do is go down to vacuum. If the partial He pressure inside the device is very low to begin with, compared to the partial pressure available when He was forced inside, it’ll take much longer to diffuse it out. That’s the scary thing about diffusing through membranes with very high gradients pointing inside an enclosed system: it’s high impossible to get it out unless you’re willing to wait.

  • @hyzercreek

    @hyzercreek

    4 жыл бұрын

    @@absurdengineering It forms a chemical compound called silicon heliide

  • @wileecoyoti
    @wileecoyoti5 жыл бұрын

    Incredible work, I had no idea these even existed!

  • @mosesturner4018
    @mosesturner40183 жыл бұрын

    The way you described the process of making these seems like near-atomic-scale 3D printing, just with only silicon

  • @I_leave_mean_comments
    @I_leave_mean_comments4 жыл бұрын

    "...and take a look at it under the electron microscope..." You have an electron microscope?

  • @andrewyoung4473

    @andrewyoung4473

    4 жыл бұрын

    This guys seems to have everything. If he says "So I pulled out my nuclear fusion reactor to test the nuclear energy..." I probably wouldn't be surprised.

  • @750kv8

    @750kv8

    4 жыл бұрын

    He made one.

  • @MatthijsvanDuin

    @MatthijsvanDuin

    4 жыл бұрын

    You don't?

  • @kevinmcnulty4848

    @kevinmcnulty4848

    2 жыл бұрын

    I have an electronic microscope in my garage I need to get working

  • @dinushkam2444
    @dinushkam24445 жыл бұрын

    WOW..! great video you should do a video series in semiconductor manufacturing at home.

  • @dinushkam2444

    @dinushkam2444

    5 жыл бұрын

    thumbs up so he will see it

  • @mada1274

    @mada1274

    5 жыл бұрын

    should produce small ics

  • @marshalcraft

    @marshalcraft

    4 жыл бұрын

    i second this notion, as basically most important topic

  • @-CLASSIFIED-
    @-CLASSIFIED-4 жыл бұрын

    this raises the question of if conformal coating over the MEMs oscillator would be good enough to shield it from helium poisoning.

  • @Sicaine
    @Sicaine5 жыл бұрын

    Always so crazy what you are able to do by your own in your own shop. Always really really cool, thank you for all the effort :-)

  • @aetius31
    @aetius315 жыл бұрын

    I think the technology used to make the buried empty space is called "Silicon On Nothing" or SON

  • @kerajit
    @kerajit5 жыл бұрын

    Applied Science == like

  • @guy12343456

    @guy12343456

    5 жыл бұрын

    Assert.assertTrue(AppliedScience == like) ; //very true!

  • @iamjimgroth

    @iamjimgroth

    5 жыл бұрын

    True

  • @GRBtutorials

    @GRBtutorials

    5 жыл бұрын

    #include "youtube.h" int main(int argc, char* argv[]) { if (argv[1] == "Applied Science") { like(); puts("Liked"); } return 0; }

  • @mousetails9
    @mousetails95 жыл бұрын

    Crazy amount of work in this 20m video. Thanks for the insight!

  • @mdouglaswray
    @mdouglaswray3 жыл бұрын

    Fascinating! Nice SEM prep - quick and effective!

  • @klasop
    @klasop5 жыл бұрын

    But I don't understand what is the mechanism how the helium makes the MEMs device to fail but not the hidrogen. :(

  • @AppliedScience

    @AppliedScience

    5 жыл бұрын

    I should have mentioned this in the video ;) My guess is that the gas pressure inside the device causes friction between the tuning fork and the stationary electrodes, and this friction causes energy loss. If the energy loss is high enough, the oscillator will not run. It's like slowing down the pendulum of a clock with your hand. It will work with some amount of energy loss (friction), but there is a point at which it will stop due to design limits on how much energy can be put into the oscillator.

  • @klasop

    @klasop

    5 жыл бұрын

    Hmm. So friction is not an issue with hydrogen, but a problem with helium? But why it doesn't happen with air? Are the major components (O2, N2, CO2, etc) of air doesn't even get into the device? Could the difference in the electrostatic properties of helium, compared to the gas already inside the MEMs device, be also a problem? Btw, thanks for the answer!

  • @lambchops808

    @lambchops808

    5 жыл бұрын

    Here’s my guess. Only hydrogen and helium atoms can squeeze through the silicon, so there is never any other gasses inside. And when it’s brought out of a helium environment, the helium will start to leak back out through the silicon, but other gasses in the air cant go in, so it reverts back to a vaccum inside (besides some remaining hydrogen and helium). I guess the hydrogen is small enough or in low enough quantities that it doesn’t affect the mechanism as much as helium

  • @PlasmaX00000

    @PlasmaX00000

    5 жыл бұрын

    Helium is a smaller molecule than hydrogen, so diffusion is much faster

  • @19855342

    @19855342

    5 жыл бұрын

    Hydrogen gas exists mostly as H2 where helium is single He atoms. So even though a hydrogen atom is smaller, in gas form it's not.

  • @MegaFPVFlyer
    @MegaFPVFlyer5 жыл бұрын

    7:04 [casually roasts imperial system]

  • @Roonasaur

    @Roonasaur

    5 жыл бұрын

    Uhhhh . . . "strange units, but at least it's KPa . . ." Uhhhh, the Pascal *IS* the metric unit of pressure . . . back up the vidjaoe, and the "strangeness" he's referring to is how the gauge measures not in absolute pressure, or even gauge pressure, as one would usually expect, but in units less than gauge pressure . . . nothing "Imperial" going on here a'tall . . .

  • @MegaFPVFlyer

    @MegaFPVFlyer

    5 жыл бұрын

    @@Roonasaur He meant that even the strange pressure measurement of the gauge is easier to work with than the imperial system

  • @Roonasaur

    @Roonasaur

    5 жыл бұрын

    @@MegaFPVFlyer Ok, sure . . . I'm American, so I guess my worldview doesn't revolve around how weird it is.

  • @RainBoxRed

    @RainBoxRed

    5 жыл бұрын

    @@Roonasaur woosh

  • @Roonasaur

    @Roonasaur

    5 жыл бұрын

    @@RainBoxRed Yeah yeah yeah, I earned that one I guess. It's YT - I frequently fire off here half-cocked lol

  • @brandonberchtold9484
    @brandonberchtold94845 жыл бұрын

    I was literally looking for sem images of these oscillators after reading that article yesterday. Good timing XD

  • @andrewferg8737
    @andrewferg87374 жыл бұрын

    In all your videos your ability to take measurements is outstanding. This is the hallmark of a true scientist; a skill set I envy but sorely lack. Thanks for sharing and for educating us.

  • @Cadwaladr
    @Cadwaladr5 жыл бұрын

    I wonder if neon would be small enough to diffuse into the thing, seeing as it's also monoatomic like helium.

  • @hyzercreek

    @hyzercreek

    4 жыл бұрын

    No way. Helium is smaller than hydrogen because the 2 protons suck the electrons closer to the nucleus than the 1 proton does in hydrogen. But neon has electrons in a whole different orbit than H or He.

  • @ytSuns26
    @ytSuns265 жыл бұрын

    Unreal, just unreal I am an ancient being. I remember testing vacuum tubes. I remember being amazed by transistors. We actually trimmed crystals to get the desired frequency. Thing is I am 67 years old, what will the next decade bring?

  • @TropicalCoder

    @TropicalCoder

    4 жыл бұрын

    I'm older than you. I remember when we used tin cans connected by strings for telephones!

  • @davebeedon3424

    @davebeedon3424

    4 жыл бұрын

    TropicalCoder Those phones had a weird dial tone!

  • @venkir1408
    @venkir14083 жыл бұрын

    you are awesome sharing the knowledge and efforts just like that with details. I really appreciate and respect you.

  • @toolthoughts
    @toolthoughts5 жыл бұрын

    awesome video, I really appreciate the work you put into this

  • @rytisbertulis3325
    @rytisbertulis33254 жыл бұрын

    The amount of effort you put into your videos is unbelievable. This is high-end quality content. Keep it up and I wish you to gain everything great you deserve doing this. Thank you :)

  • @blahblahblahblah2933
    @blahblahblahblah29335 жыл бұрын

    Ne is only slightly larger; got any lying around?

  • @djpanther9621
    @djpanther96215 жыл бұрын

    Love your videos! Very educational and nicely delivered. *just happens to have an SEM* lying around 😀

  • @GenericGerman
    @GenericGerman5 жыл бұрын

    I didn't even know that I didn't know that. The more you learn.. Thank you! This was great!

  • @ElGordoMaton
    @ElGordoMaton5 жыл бұрын

    The "S" in MEMS should be capitalized. MicroElectroMechanical Systems. PD: great video

  • @bobsagget823

    @bobsagget823

    5 жыл бұрын

    nobody cares

  • @Anvilshock

    @Anvilshock

    5 жыл бұрын

    Certainly you don't.

  • @drivejapan6293
    @drivejapan62935 жыл бұрын

    Try neon. Its the second smallest atomic radius I think. Might permeate in faster than hydrogen to see a second fail gas. Its still not near as small as helium though.

  • @penroc3
    @penroc35 жыл бұрын

    so excited when i see you posted a video

  • @vinayramasesh2959
    @vinayramasesh29595 жыл бұрын

    Amazing video and explanation, thanks!

  • @MauriceChavez353
    @MauriceChavez3534 жыл бұрын

    So can you overclock your smartphone with a 0,05% atmosphere Helium booster shot?

  • @turf6863

    @turf6863

    4 жыл бұрын

    Yes, you'll get a 0.00152587890625% increase of your phone performance. But it'll wear off within days and you'll have to re-apply it.

  • @erezra
    @erezra5 жыл бұрын

    So why does the Helium stop the oscillator? Does it diffuse in and cause drag?

  • @RobertSzasz

    @RobertSzasz

    5 жыл бұрын

    It changes the physical parameters of the crystal.not really drag as you aren't moving crystal dislocations around

  • @KallePihlajasaari

    @KallePihlajasaari

    5 жыл бұрын

    If the MEMS 'tuning fork' is made to work in a vacuum then the presence of any gas will cause a huge amount of damping. It may even cause current to flow between parts that are supposed to be insulated resulting in no force generation or shorting of the pick-up signal to the common.

  • @RobertSzasz

    @RobertSzasz

    5 жыл бұрын

    @@KallePihlajasaari well, some damping anyways. Most MEMS are small, but not That small. And these devices are designed to run in atmosphere.

  • @alexanderdaum8053

    @alexanderdaum8053

    5 жыл бұрын

    @@RobertSzasz MEMS oscillators will always have a vacuum inside, the little "tuning fork" would not be able to oscillate in atmosphere

  • @jamesbrewer3020
    @jamesbrewer30205 жыл бұрын

    Very interesting. Thanks for all the info. All of your videos are fascinating. Thank you.

  • @jimlarsen6782
    @jimlarsen67824 жыл бұрын

    Excellently detailed presentation. Thanks!

  • @elliotts9782
    @elliotts97825 жыл бұрын

    Is there a way to use this phenomenon to measure the exact concentration of helium in any given environment?

  • @RobertSzasz

    @RobertSzasz

    5 жыл бұрын

    There are similar sensors,

  • @Basement-Science

    @Basement-Science

    5 жыл бұрын

    As a sensor this would be too slow, but I´m sure you could make a sensor in a similar way.

  • @Mrluk245

    @Mrluk245

    5 жыл бұрын

    take some Iphones and avarage the times they need to stop working. I am sure you can correlate this value with the amount of he in the air^^

  • @designworksdw1949
    @designworksdw19495 жыл бұрын

    Do you post your electron microscope images anywhere?

  • @AppliedScience

    @AppliedScience

    5 жыл бұрын

    I added it just now: drive.google.com/drive/folders/1l3mJ4UTs8aY70scH7vDaf0M8pLeP2kqI?usp=sharing

  • @designworksdw1949

    @designworksdw1949

    5 жыл бұрын

    @@AppliedScience Thank you i find that image of the mems device just amazing

  • @jlippencott1
    @jlippencott14 жыл бұрын

    Back in the old days (50's) while working with high vacuum (10^-5 and below) we were surprised to find that the glass diffusion pumps were unable to get below a certain level no matter how long the pump was running. When we simply switched over to metal diff pumps without changing anything else, it got much better. We were told the issue was likely diffusion of atmospheric helium through the glass walls of the pump keeping the pressure up. We routinely used helium as a trace gas for leak detection in our mass spec. leak detectors.

  • @TheBdd4
    @TheBdd45 жыл бұрын

    Applied Science: Thank you for so many interesting and useful experiments and demonstrations. You are a very bright and talented guy.

  • @theevilovenmit
    @theevilovenmit5 жыл бұрын

    So these are tiny helium sensors.

  • @laharl2k
    @laharl2k5 жыл бұрын

    it only went up by 0.5Hz, and i was thinking that maybe we could overclock non-overclockable stuff by putting it in 1% He >_>

  • @Gaark
    @Gaark5 жыл бұрын

    bloody amazing how small things are getting, fascinates me

  • @aland1618
    @aland16184 жыл бұрын

    Nice presentation and conclusion. Stuff I didn't know but now I do. Thanks.

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