Tunable Stiffness Compliant Mechanism with Bistable Switch

Tunable Stiffness Compliant Mechanism with Bistable Switch - Binary Stiffness (Part 3)

Рет қаралды 228,597

2 жыл бұрын

This video depicts a translational binary stiffness compliant mechanism that achieves two different states of stiffness by being triggered using a simple bistable switch. One state is very compliant while the other state is very stiff. The mechanism was designed by Reinier Kuppens while working in my lab at UCLA as a visiting scholar from Delft University.
Further details about the mechanism are published in the Journal of Mechanisms and Robotics, and can be found at this link:
asmedigitalcollection.asme.or...
A raw video of this mechanism was previously uploaded to Reinier’s KZfaq channel:
• Fully compliant static...
but this video is intended to explain the mechanical principles behind how the mechanism works. This video is the third part of a five-part mini-series about binary-stiffness compliant mechanisms. Be sure to watch the other parts to learn more about how they work and for what applications they could be used.
The part files for this mechanism can be downloaded from Thingiverse at this link:
www.thingiverse.com/thing:543...
Also, to understand more about compliant mechanisms in general, be sure to watch the other videos in my Compliant Mechanism Design series on this channel.
Acknowledgements:
This video would not have been possible without the brilliance of Reinier Kuppens, Just Herder, and Miguel Bessa, so a huge thanks to them.
Donate to help support my channel:
If you’d like to make a one-time donation, you can use the following link:
PayPal.me/FACTsMechDesign
Thank you for your support! It is much appreciated and helps enable me to make more content.
Disclaimer:
Responsibility for the content of this video is my own. The University of California, Los Angeles is not involved with this channel nor does it endorse its content.

Пікірлер: 160

@PianofortheSoul122 2 жыл бұрын

My dear son, I love hearing your delightful voice narrating genius videos like this!

@AddisonLarson 2 жыл бұрын

Yeah mom, he's doing a good job.

@fukkenPavlo 2 жыл бұрын

Son to be proud of :)

@Realience 2 жыл бұрын

Who is this? Am I just dumb?

@ApoloLiurk 2 жыл бұрын

that's cute

@Ozhull 2 жыл бұрын

Awww such a wholesome comment :)

@samheasmanwhite 2 жыл бұрын

I recently repaired a Willomore seismometer that uses this principle to almost completely eliminate the stiffness of the springs that suspend the weight. There is almost no force returning the weight to centre when it is properly tuned so it's resonant frequency can be less than 0.1Hz, to pick up those really slow earthquakes.

@soorajkadnor4642 2 жыл бұрын

These kind of mechanisms will bring a revolution in our technologies. Keep it up.

@gabethedinosaur5477 2 жыл бұрын

I'm entering my first year of college as a mechanical engineering major; it's videos like these that inspire me to design my own mechanisms and pursue the oddities of classical mechanics! Thank you!

@alextheferret5674 2 жыл бұрын

Nice! I'm planning on going to college for mechanical engineering as well!

@Lecsi11 2 жыл бұрын

@@alextheferret5674 let's go guys! It will be cool. I'm near to finish my studies as a mechanical engineer :)

@jameshopkins21 2 жыл бұрын

Jonathan, I love your videos! It appears to be taking off like wildfire. Congratulations!

@mohsena5900 2 жыл бұрын

Congratulations for your success in this project. As always it's amazing to watch your innovative projects

@lohikarhu734 2 жыл бұрын

Hey Jonathan! I had "followed" your work for a long while, but just found this channel today! Nice to see you making this interesting work both accessible and understandable, on this platform. I have often seen designs in industry, using "classical" bearings and sliding mechanisms, that could really have benefited from proper application of flexure-based designs... Hope that you're keeping well, and that life is treating you well!

@MaximusCensorius Жыл бұрын

I love learning, and with your channel, I am never disappointed. Thank you! Happy New Year!

@andramoie 2 жыл бұрын

The pacing of the explanation is perfect. Well done!

@darth_dan8886 2 жыл бұрын

I've seen compliant deformation mechanisms before, but this one finally explains the concept, and now I really want to find a way to implement it in a practical application...

@Adamsmasher23 2 жыл бұрын

This is very cool, thanks for sharing and for the detailed and accessible explanation!

@swedneck 2 жыл бұрын

oh wow this actually went from utterly inscrutable to obvious after that explanation, that's impressive!

@TracyNorrell 2 жыл бұрын

I hope to come up with a project to use this soon. Very cool. Thanks for this series

@harriehausenman8623 2 жыл бұрын

Super amazing and cleverly explained!

@3DPDoctor 2 жыл бұрын

amazing explanation

@jbrownson 2 жыл бұрын

Excellent explanation, thanks!

@Jacob_graber 2 жыл бұрын

Great presentation and animations.

@romaincorthesy6896 2 жыл бұрын

Those are such interesting principles !

@ajinkyamahajan102 2 жыл бұрын

It is impressive. Thanks again for a great video 😊😇 Cheers

@plazmaguy13yago9 8 ай бұрын

incredibly intresting video

@Sverreification 2 жыл бұрын

Do you have any guides for how to design/model your own flexure mechanisms in e.g. Solidworks or other CAD software? Very cool video/paper, thanks!

@Andersmithy 2 жыл бұрын

no idea why this showed up in my feed, but very cool nonetheless. I couldn't figure out why you'd want something like this until the end where you showed the "self-switching" ability of the device. Then it 'clicked' for me!

@ESS284 2 жыл бұрын

This is fantastic thank you, and i suspect working through the material you have made available is going to have a big impact on me. I wonder if you could kindly let us know which plastic are you using for the demonstration mechanisms please?

@BresStephane 2 жыл бұрын

This is amazing

@MrMaxkingone 2 жыл бұрын

Thats insanly cool

@Speed001 2 жыл бұрын

Great video. I've had some interest in compliant mechanisms since I was first sold the concept, maybe it'll be useful one day.

@goodiesohhi 2 жыл бұрын

I'm glad youtube decided that THIS was was something I needed to watch haha.

@wolpumba4099 8 ай бұрын

amazing!

@darkling-studios 2 жыл бұрын

why am i here, when did i get here, i have never once over the course of my entire life sought out mechanical design or the application of stiff and non stiff mechanisms, but i watched, i understood, and i was intrigued the whole time.

@yassinechih7620 2 жыл бұрын

Just the best in youtube

@Fight2Survive559 2 жыл бұрын

that looks awfully like a zener diode plot. I bet you could set it up with a damper on the force input to make a easy force regulator

@DB-ns6dk Жыл бұрын

Wow. Very cool.

@sinuture 2 жыл бұрын

This is really interesting idea! It might realise “physical computer” as I have seen a computer by using water flow. Computers without electron excite me.

@paulromsky9527 4 ай бұрын

That plot at 1:14 is similar to a Zener Diode. Current is the Y axis and voltage is the X axis. When a Zener Diode is reversed biased, at certain point in voltage it will remain constant over a various change in current (the left knee in the graph - the Zener point). That is how Zener Diodes regulate voltage.

@TheJonititan 2 жыл бұрын

It seems these could be used in a way analogous to a resettable mechanical fuse.

@childintime7 2 жыл бұрын

Love the concept! Can you plz upload the .stl Thank you

@AmusementLabs Жыл бұрын

Hello, I wanted to ask what song/track you used during this video? I really like it. :)

@aaronclair4489 2 жыл бұрын

The application I thought of first: a vehicle suspension with a stiff on-road mode and a soft off-road mode. There are other ways to accomplish this (pneumatics, hydraulics, electromechanics), but this mechanism could probably build a two-mode suspension with just springs and shock absorbers.

@Calligraphybooster 2 жыл бұрын

I like this idea. Instead of a dovetailed bar you could insert an elliptical dial and fluently change characteristics.

@polarbearchimney 2 жыл бұрын

This looks really cool. I'm just very confused about what you could use something like this for.

@j-b-l8147 2 жыл бұрын

whenever a video starts with "This..." I can only think of Doug

@namename8004 2 жыл бұрын

Anytime I have a system that needs stiffness cancellation, I just think about baseball or my grandma. Works every time!

@RatkingNyxu 2 жыл бұрын

My mind immediately went to a failsafe mechanism or perhaps even a prop-knife. Producing a compliant mechanism that allows the blade to appear rigid until enough force is applied- at which point the bistable mechanism causes the blade to retract freely could be incredibly useful.

@sebimoe 2 жыл бұрын

Not sure about need of this in knife, maybe some type, but if you apply a lot of force, you may use your finger on side of the blade to stabilise it, and then it could slice you if your grip extends to the edge a bit

@makerbeelab5546 2 жыл бұрын

Do you have these somewhere in STLs? I would love to print them and play

@pauljs75 2 жыл бұрын

Looks like something that could be used for a valve, perhaps inside a dampener?

@microcolonel 2 жыл бұрын

I would love to see the kind of performance that you could get out of these mechanisms cut out of steel. I think it would not be difficult with jet or laser cutting.

@Mathiasosx1 2 жыл бұрын

It is possible to 3D print with certain metals as well

@ChaosNe0 2 жыл бұрын

I love mechanisms like this. The yet overviewable complexity for even simple behaviours is a special kind if aesthetic. But there's a question always on my mind when I watch videos like this one: Doesn't the material get tired over time? I imagine it would either adjust to the forces applying when idle or simply break, no matter how frequently the product is used. So how long is such a mechanism functional? Or are my assumptions wrong and it will never break without outside force?

@pockpock6382 2 жыл бұрын

Didnt think this would make me go "thats so cool!!" but it did

@Takyodor2 2 жыл бұрын

Usually, bendy things wear out from fatigue. I'm guessing something about the materials and/or design here prevents wear? How, and how many cycles can be expected? Super cool mechanism!

@bontonswanson8977 2 жыл бұрын

I think that the plastic these are made from is just good enough for a prototype, and the final product would likely best highly elastic metal such as inconel

@ciarangale4738 2 жыл бұрын

Im no engineer, but to my limited knowledge there would probably be a significant difference in wear between flexing and bending. as such, it could probably be designed so that it would more than outlast its intended lifespan

@Hephera 2 жыл бұрын

ahhh yes. I'm back in the weirdly specific part of the youtube recommendations again

@ubza1234 2 жыл бұрын

I saw a video, and it demonstrated a device that used flexures to create a linear motion in just one direction and was constrained in that one direction. It was not possible for movement in other directions. It had two pairs of flexures, one pair to an anchor point, and two to the moving part with a third point connecting the free end of the flexure pairs. At rest, all flexures were parallel. If this rings any bells, I'd love the name of this mechanism. I've been searching KZfaq for the video and going through my history with no success. Any help would be greatly appreciated!

@Graham_Wideman 2 жыл бұрын

That kind of flexture might be called a "linear stage". You might like a video on Dan Gelbart's channel "Building Prototypes Dan Gelbart part 10 of 18 Flexures".

@ubza1234 2 жыл бұрын

@@Graham_Wideman Thank you so much. I'm slowly chipping away at watching all the videos on your channel. They are very inspiring. I have a project that requires linear motion in a single direction only, and that can keep it rigidly constraining it in just one direction. Space constraints are an issue and the traditional technique for this particular problem are not possible. Your videos are inspiring me to think in new ways, to contemplate nontraditional,novel solutions and to build mechanisms myself. (using my laser cutter) thanks for these videos!

@Graham_Wideman 2 жыл бұрын

@@ubza1234 It's not my channel. I'm just an interested viewer and commenter :-)

@ubza1234 2 жыл бұрын

@@Graham_Wideman Oh 😂 well, It's nice to know that there are people in this community who want to help each other. Thanks for the help!

@Graham_Wideman 2 жыл бұрын

@@ubza1234 You're welcome! - I think it's cool that others share an interest in these videos, and intriguing mechanisms!

@rock3tcatU233 2 жыл бұрын

Very interesting, have there been any practical applications proposed for this mechanism?

@TheMooStashe 2 жыл бұрын

Been wondering the same. It would have been a nice addition to the video

@ciarangale4738 2 жыл бұрын

I recall seeing something similar some time ago, which was submitted as part of the trigger for nuclear weapons.

@dimitar4y 11 ай бұрын

I can see this being used as the hinges for self-leveling lasers.

@glz1 2 жыл бұрын

This is the future

@dubsar 2 жыл бұрын

Make it a few nanometers.

@elimain1261 2 жыл бұрын

@@dubsar it can be made a few nanometers. Compliant mechanisms can be crafted onto microchips.

@ktkace 2 жыл бұрын

Would like to see real world examples of how this system is used.

@jelloshot 2 жыл бұрын

do you think enough of your designs exist now to train an ai model to make these when given certain input parameters(linear translation with x force, rotation about point y, etc)? ive seen some things around about algorithmic optimisation, are we at fully generated designs yet?

@timothypryor7952 2 жыл бұрын

This is very interesting technology. What is a practical application of this technology? Where might we see this technology implemented?

@timothypryor7952 2 жыл бұрын

For those wondering, this is called the "price of bread test". IE what does all this have to do with the price of bread.

@demonbeast85 2 жыл бұрын

this was recommended to me by youtube randomly. it sounds interesting but i have no idea what it is for or where it would be used. would someone be so kind and brefly explain where thoes Bistable Switch could have a use, without getting too much into details? please and thank you

@Xerkies Жыл бұрын

The tensegrity table is a similar principle? Of course, without the switch.

@jedics1 2 жыл бұрын

Fascinating, but what is the use for this?

@ZackfilmsV2 2 жыл бұрын

Are any of these compliant designs available for download so I could print them?

@TheLightinTheDarkness2565 2 жыл бұрын

This would be a good switch for an airbag deployment system.

@calvinthedestroyer 2 жыл бұрын

You should make one using truck leaf springs!

@juangoyeneche7304 2 жыл бұрын

More than understanding is what is the practical use for any of these mechanisms?

@samheasmanwhite 2 жыл бұрын

I just repaired an old Willmore seismometer that uses stiffness cancellation like this to tune out the stiffness of the main spring and the flexures that holds the weight. That lets it tune the oscillation frequency down below 0.1Hz for picking up those really slow earth movements. Flexures in general are not at all common, but in the areas they are useful they they tend to be by far the best solution.

@andrewwatts1997 2 жыл бұрын

Can these mechanisms be used in MEMS devices ? To cunstruct micro mechanical structures.

@TheFACTsofMechanicalDesign 2 жыл бұрын

Absolutely!

@quarry1030 2 жыл бұрын

so the diaphragm plate in a clutch?

@El-Burrito 2 жыл бұрын

What's the practical use of this?

@dae67 2 жыл бұрын

basically the stiffness is capped to the stiffness of the bistable compliant, then it turns to 0 when the bistable is off. The value of the stiffness of this machine equals the stiffness of the bistable till reset?? Ps. the reset can be a lever blocking the bistable on his free axis, but you need to apply the same force needed to "unlock" it, am i right?

@xaytana 2 жыл бұрын

'Tunable' seems a bit misleading, as it implies you can tune the mechanism, such as tuning an instrument. What's shown here is still just a binary, otherwise untunable, switch with some extra pieces on it. One would expect a 'tunable' mechanism to be able to be somewhat precisely manipulated until an optimal point is reached, again like tuning an instrument, or using a potentiometer in a circuit to achieve a required voltage, a dimmer on a light switch to achieve a preferred brightness, etc. Though, I can see how you wouldn't be able to do this with a singular compliant mechanism, at least not with one that's simplistic in design.

@radadadadee 2 жыл бұрын

would "switchable" be a better word than tunable then?

@xaytana 2 жыл бұрын

@@radadadadee Yes, because that's literally what this is, a binary switch. Similarly, having a third position would be a trinary switch, and still not a tunable mechanism. A mechanism isn't tunable until there's fine control of what you're tuning. Problem with this is that typically it would require a secondary non-compliant part within an assembly with the compliant part, such as using a screw to adjust tension or stiffness. There's also the possibility of using multiple switches in steps, or having a compliant stepped mechanism to act as a multi-position switch, but the difference between the discrete steps needs to be fine enough to emulate what a proper tuning mechanism could do, otherwise it's just a n-position switch. There's the possibility of using something like a watch spring with a locking button to adjust tension with a positionable part, but then reliability and holding strength of the button, which then becomes complex in it's own way based on other requirements; there's also complexity in manufacturing here, as you now have a compliant button on a plane perpendicular to the spring's pivot, of which is also perpendicular to the mechanism's range of movement, and that's just for a one degree of freedom mechanism. A truly tunable compliant mechanism is so much more complex than a binary switch, and this is before getting into the complexities of how the flexures behave under varied amounts of tension, one could very easily buckle incorrectly and ruin the intended outcome of the mechanism.

@JosephProsnitz1 2 жыл бұрын

I just don't get it. I wanted to make a compliant based fan with "wings" and I don't understand what I would need to do

@martinblank1484 2 жыл бұрын

"Principals of stiffness cancelation"...need to remember this for my wife...

@anasqai 2 жыл бұрын

What material is it? The flexibility unbreakable? A metal coated plastic? Like mini snake robot?

@anasqai 2 жыл бұрын

At 3min 29s issit like a release to Jump a robot? The leg to be able to jump, then pull to reset(ready to jump)?

@anasqai 2 жыл бұрын

At around*

@boredwools2158 2 жыл бұрын

Really neat that I didn't understand a single word in this title

@kaylaa2204 2 жыл бұрын

Sir, my qualifications are in software engineering, I came upon this by mere coincidence What is the purpose of this? I understand how it works just fine from your explanation. My only question is "Why is this useful?"

@fitrianhidayat 2 жыл бұрын

I misread the title as "turntables" and thought "well, how TF is this gonna work in a turntables?"

@bobsagget823 2 жыл бұрын

holy shtt

@Gunth0r 2 жыл бұрын

KZfaq's algorithms rightly assumed that this would trigger some sort of kink in me. I find this very erotic. Thanks, KZfaq!

@addammadd 2 жыл бұрын

Here I was under the impression stiffness cancellation involved thinking about math and baseball.

@SampleroftheMultiverse Жыл бұрын

The producers might like my video on a related method. It uses my variation of Euler’s contain column theory.

@SampleroftheMultiverse Жыл бұрын

kzfaq.info/get/bejne/rdhyptSaqpbad2g.html

@gmartineza8775 2 жыл бұрын

Cherry MX compliant when

@ausrabernote5914 2 жыл бұрын

🐝💤💥❤💫👍

@mandarbamane4268 2 жыл бұрын

0:48 me (Electronics Engineer): Hmm... zener diode V-I characteristics

@MortenSahlMadsen 2 жыл бұрын

hø hø... Stiffness...

@SzymonGroth 2 жыл бұрын

One word. STIFFNESS.

@MaeveMoore 2 жыл бұрын

this is basically an extension of mems

@davidcahan 10 ай бұрын

Short bar, Long bar. Eazy Peezy!!! 😢😮😅

@TheTechAdmin Жыл бұрын

My Ex is an expert in stiffness cancelation.

@thetruthexperiment 2 жыл бұрын

Can’t you just SEE how it works? It’s like those “floating” tables. It’s cool but obvious if you look at it.

@Phantom-bh5ru 2 жыл бұрын

I don’t need sleep

@tureba 2 жыл бұрын

The narrator's voice sounds like David Foley.

@joshuavinesett5013 2 жыл бұрын

You said stiffness

@noahway13 2 жыл бұрын

Once I hit 50, I need all the stiffness I can get...

@Mecryte 2 жыл бұрын

This design seems flawed. A sufficiently powerful force could switch it to it's compliant state if the input were forced over the switches tripping point. I think it would need to be redesigned so that the switch could be independent of the input

@Electric_Bill 2 жыл бұрын

I had the same thought

@ciarangale4738 2 жыл бұрын

was this not intentional? it seemed the middle portion was designed to toggle when sufficient force was put upon the input

@Mecryte 2 жыл бұрын

@@ciarangale4738 It's implied that the input will not move until a toggle happens. If that can be overridden, then the design fails.

@ciarangale4738 2 жыл бұрын

@@Mecryte What of the demonstration to the right hand side of the screen at 3:30 ?

@Mecryte 2 жыл бұрын

@@ciarangale4738 Somehow, I missed that.

@illitero 2 жыл бұрын

Stoked to see these kinds of designs inevitably swallowed up by Capitalism and used to fight the Corporate Wars in 2037

@qaz3433 2 жыл бұрын

It feels weird when things that seem like common sense are broken down.

@justayoutuber1906 2 жыл бұрын

My ex-wife gives me serious stiffness cancellation.

@commoncommentatingcommento8683 2 жыл бұрын

Not sure how i got here…

@ragnarok7976 2 жыл бұрын

Mechanical digital computer made out of flextures, anyone?

@lohikarhu734 2 жыл бұрын

BTW, I comment on KZfaq with a pseudonym, so you would not, sadly, recognise me from emails in our history ;-)

@marklatimer7333 2 жыл бұрын

Is there some kind of Video Making Instruction book somewhere that says "All engineering interest videos MUST have an extremely annoyingly and overly loud background music track" ? - It made this unwatchable for me hence a solid 'dislike'.