4D Knit Dress | Hacker News Reader

4D Knit Dress

selfassemblylab.mit.edu

237 pointsgeox80 comments

"heat-activated yarns"

That's how much tight-fitting clothing is made. Raw spandex has about a 10x stretch. But hot air will re-set the neutral point of the stretch. So stocking, etc. are made by weaving a partially-shaped garment. That's then slipped over a metal form that's the size of the garment when un-worn. The form and garment are hit with hot air for about a minute, and that re-sets the zero point of the spandex.

Here's a pantyhose production line.[1] Forms and heat transform it from a crumpled mess to a formed garment.

[1] https://www.youtube.com/watch?v=wlzj9dy5PhA

I feel like adding heat shrink fabric doesn't add a dimension and make it go from 3D to 4D. I was expecting a klein bottle or hypercube projection or something.

Both of those items are 3D - while the dress transforms over a 4th time dimension.

Don't all dresses transform over time?

Eventually 100% of all possible dresses will transform into dust.

What about dresses repurposed into non-dresses prior to their dusty demise.

Eventually those will too.

I mean everything transforms over time.

Reminds me of https://xkcd.com/209/

"So the kayak travels through time?"

"Sure! Just like everything else!"

This applies to everything so it’s moot.

No, a Klein bottle is an object that can not exist in 3d. The one you probably know is an "immersion" into 3d (making the object intersect itself, which it wouldn't do in it's original shape in 4d)

I don’t suppose it’ll help at all if I say that a Klein bottle is a two-dimensional surface and four is the smallest dimensional Cartesian space into which it can be embedded.

A question for people who know more topology(?) than I do: what determines this? Is it possible to construct a surface that requires an arbitrary number of dimensions for its embedding?

Good question. Based on googling [0] it looks like any surface can be embedded in four dimensions (and any n-manifold can be embedded in n+2 space). But I don’t know enough to explain the construction. Might have something to do with the tangent bundle, it sounds like?

[0] https://math.stackexchange.com/questions/2960093/why-do-we-n...

If by surface you mean a 2-dimensional manifold, then no. The Nash embedding threorms give upper bounds for how big the embedding target dimension needs to be for any n-dimensional manifold. In the case of 2-dimensional surfaces, at worst you'll need 51 = 2×(2+1)×(3×2+11)/2 dimensions. Mind this is for isometric embeddings (ones that don't squish things around in a sense), which is kind of the most stringent constraint possible. If you allow squishing things around, then the upper bounds get even smaller.

https://en.wikipedia.org/wiki/Nash_embedding_theorems#Ck_emb...

Does it really though? The heat setting process doesn't seem reversible so it's just one step in the initial manufacturing and after that it doesn't seem to be expected to change.

I don't think that you get how revolutionary this is. It has the potential to wholly take over all clothing production, for the sole reason that it can be fully automated.

That's fine but it doesn't make it a 4-dimensional object.

It’s like 4D armrests. ;)

Finding more detailed information has been annoying.

From https://www.dezeen.com/2024/02/09/4d-knit-dress-mit-ministry... it says that the heat shrinking material is nylon, while the rest of the yarn is a viscose + polyester blend.

Does that mean the transformation is permanent? Because if they created a dress that could be shaped, unshaped, and reshaped in different ways using, say, a hair dryer, they'd really be on to something!

I think it means that it's basically permanent - it cannot be unshaped. You can of course keep "tucking it in".

Need to include a few strands of something like https://www.asme.org/topics-resources/content/metal-that-rem... .

There are also memory alloys which can remember two states.

A similar concept is supertwisted nylon fishing line "muscles" which contract upon heating.

I think starfish muscles are contracted in the default/energy-off mode, so maybe we could make smart fibers which are actively elastic/"plastic".

Nylon is thermoplastic so in theory it could be reshaped but the filament would lose a lot of strength and durability in the process

It's a very cool idea at first, but how would it work in practice? Would your dress lose its shape if you wore it for a long time? Or in cold weather?

I’m curious how the flexibility of the reformed fabric lasts over dressing/undressing cycles, garment care, and long term storage in a closet. If I’m not careful I can easily stretch out a well made alpaca wool sweater if I remove it too carelessly (from experience!). I wonder how fussy this is.

Also would like to know more about the machine. Many garments are knitted as tube-like structures just look at circular knitting needles, where does this differ and how?

It doesn't seem like this is intended to be reusable or even useful.

It's just a college design project that gets the attention of MIT branding.

Maybe so, but the 6-axis machine appears to be sitting in the front window of a store on Newbury St. (which is Boston’s high-dollar shopping area).

its like making nylon stockings but a dress, there is a video that shows the process that would answer a lot of your questions on the site near the bottom of the page

Ah very cool thanks!

How disappointing. Today it's all polyester, polyester and more stinky polyester. Tomorrow the washing machine has it ground to dust already, forever. Lucky us, this single-use dress is of bespoke fit!

The "4d" refers to the knit, which finishes knitting itself after a bit of time. I thought it was like some klein bottle dress or something at first. Still cool.

My reading of this was that the fourth dimension was time. First, a loose dress is 3D-knit; then, when the owner buys it, it's possible to apply heat to cause parts of the fabric to tighten up, overall making a bespoke fit without significant manual labour.

I'm not entirely sure how much labour is saved vs making it custom cut from the start, having to stand in the reach of an industrial robot and get blasted with a heat gun doesn't seem like a great customer experience... presumably all the relevant measurements had been taken ahead of time so a tool-path for the robot could be created

Seems less about saving labor and more about proving technology.

You could take this concept a step further and 3d-scan the subject body with a laser, then 3d print a model, and the clothing draped on the model and heat-shrunk (rather than using a software to decide where to heat shrink and how much)

It’s shrink-to-fit denim, with a 3d pattern. Instead of wearing your dress in the bathtub, you hang it up and a robotic arm blow dries it

So you _must_ wash it with cold water, I guess

Along with your 4D woolly jumpers

Watch out for tetrachromatic colors, they can bleed.

Wash it? Toss it into the recycler and print a fresh one tomorrow morning :)

The video show a heat gun at fairly close range shrinking the fabric, which would be over 80 degrees. You might be able to get away with hot water, but I suspect the label will say 'dry clean only'.

synthetic fabrics in clothing are a major source of microplastics exposure. In the future we will look back in horror at this whole industry.

I wonder if the plastic we deposit into the environment will form oil/coal deposit layers in a few million years? Or will microbes develop means to digest all those energy rich hydrogen carbon bonds those polymers are composed of. Much like our coal/oil deposits date back to before evolution a means to metabolize cellulose.

I guess it’s my turn to point out the lignin indigestibility hypothesis is no longer current and indeed has been disputed since the 1990’s.

This article from 2016 goes into the details:

https://www.earthmagazine.org/article/lack-fungi-did-not-lea...

>To form coal you need two basic conditions: wet tropics and a hole to bury organic matter in for a long period of time,” Boyce says. During the formation of Pangea, collisions between continents raised mountain ranges while downwarping adjacent crust, which created massive basins. These basins became ideal depositories for wet organic plant matter, which was buried, compressed and cooked over geologic time to form coal. Similar conditions likely also produced coal deposits during the Mesozoic Era, and the Paleocene and Eocene epochs, often in conjunction with mountain-building episodes such as the formation of the Rocky Mountains.

This is the first time I've heard this, so I'm glad you're taking turns.

Also a major source of clothes falling apart. My ever since Levi’s made their pants stretchy, they’re absolute shit.

Everything is a compromise: making pants slightly stretchy makes them fit better, but like everything, there's a downside, being reduced lifetime in this case.

While impressive as a concept and technology I have doubts about reducing "excess waste, additional cost/labor" part. Sure might be using less material & time for the dress itself, but if it is really meant for customization they will need to create the model/mannequin of each individual customer.

Did they talk about cost anywhere? Depending on it, it could transform the industry or it could be totally irrelevant.

Spoiler: it will be the latter

The text contrast on this website is awful.

This reminds me of Vi Hart's hyperbolic dress. It's not too similar to the knit dress here, just vaguely mathy + clothing.

Ministry of Supply has always had great products, more people need to know about them.

Trying to decide whether in Newspeak* the brand would be "Ministry of Demand" or "Ministry of Scarcity".

Given that their work travel guide and versatile "capsule" complete with backpack is great:

https://www.ministryofsupply.com/about/travel-light-guide

Let's go with "Ministry of Demand".

* Actually, it was named after another Ministry of Supply of the same era as the inspirations for 1984's ministries. But, not really doublethink, more about material technologies: https://en.wikipedia.org/wiki/Ministry_of_Supply_(clothing)

hmm 4D clickbait

The haptic sleeve is more interesting!!!

it needs to be crossed with: https://news.ycombinator.com/item?id=39649184

NOT A FAN.

Its both terrifying and amazing.

Im going with terrifying.

But, also, this is how Mecha works... but in anime the pilot is inside the robot.

Teleportation is Avatar... but yeah, now its a reality is super FN scary

---

WAIT: what was that movie with Dexter where they controlled prisoners though such as a game... its a brilliant movie...

We are still making clothes like savages, with the only improvement being the economy of scale. We should enter a store, take a instant 3d scan, then get clothes that are custom made to size, seamless knitted, of our choice materials, properties, colors.

3D scanning is getting there, e.g. https://www.aistetic.com/ in UK which is being by a few online retailers. At least helps with fit and reduces returns burden. Getting from that to custom printed clothing is certainly and interesting idea if the economics ever work out.

Bonobos has physical "Guideshops" [0] that do not carry all inventory, but should carry a majority of the fits and sizes offered by the brand. The idea is that you go in to find the right fit, then you order your preferred color online. This reduces physical inventory in stores.

Made-to-Measure is also becoming increasingly popular. While costly compared to brands like Gap and Uniqlo, often you can get well-fitted made-to-measure garments for similar prices to mid-tier brands. For example, SuitSupply [1] offers made-to-measure dress shirts, trousers, and suits for only slightly more than their off-the-rack offerings, and FITTED Underground [2] offers made-to-measure jeans that are still in the price ballpark of premium selvedge jeans. Usually, these brands also let you customize things like button colors, cuffs, collars, monograms, etc. at little-to-no extra charge.

Even some shoe brands like Beckett Simonon [3] and BLKBRD [4] operate on made-to-order models, reducing inventory, and sometimes allowing customization.

All these options still rely on traditional manufacturing, but just the fact that you can get the fit right allows people to consume less.

[0] https://bonobos.com/guideshop

[1] https://suitsupply.com/en-us/

[2] https://fittedunderground.com/

[3] https://www.beckettsimonon.com/

[4] https://www.blkbrdshoemaker.com/

I am still searching for reasonably priced T-Shirts that only have seams from the armpits to the hips (one such seam per side), and optionally at the 4 holes for edge reinforcement. Critically, this means no seams on top of shoulders by any reasonable definition of what "on top of shoulder" means.

You could knit it on a tube knitting machine capable of adjusting loop count/circumference freely.

But for a T-Shirt you have very fine knitting, so regular knitting machines can at best do newborn-sized T-Shirts.

If anyone happens to know where I could order a dozen shirts knitted to spec based on knit design rules and published-by-them loop-pitch-after-first-wash from cotton, I'd love to hear.

What is the reason for not wanting the seams on the top of the shoulders? Aesthetics? Weightlifting?

Not seamless, but:

There are a lot of brands that offer t-shirts with "raglan" sleeves where the seam runs from the collar to the bottom of the armpit, instead of along the top of the shoulder.

Or: I personally have a number of the Durable Shirt from Ten Thousand [0], which has 2 seams on the front and back of the shoulder instead of 1 directly on top. This is so you can put a barbell on your shoulders comfortably, but I also like the aesthetic. It also looks like they are currently out of stock on these, but maybe they'll have more in the future.

[0] https://www.tenthousand.cc/products/durable-shirt?variant=39...

I had to look up raglan sleeve (it refers to the pieces of fabric and where they are stitched together, not the 2-tone colors which do make it easier to see)

https://gothaesthetics.com/wp-content/uploads/2020/12/RAGLAN...

The ultimate in fast fashion. The result might be a massive pile of discarded clothes that fit no one unlike now when discarded clothing is bought and sold sometimes several times over.

Plus you have to bear in mind that for many people having to make decisions about style, fit, material, colour, pattern is a burden not a pleasure. People just want a new pair of jeans to replace the ones that got damaged so next time they are in Tesco's or Sainsbury's they just grab one off the rail and throw it in the trolley.

Wouldn't a fitted shirt just turn into an unfitted shirt? Why would clothing made to fit someone somehow fit someone else much worse than the standardized unfitted clothing?

Because unfitted clothing is generally designed so that it will fit less closely. Tailored clothing generally fits more closely so that anyone buying it second hand would need to be closer to the proportions of the original owner.

The amazing part is that you're so close, but you're still thinking like a savage: why would you go into "a clothing store" for this? You take a 3d scan at home, and send that over to the print-on-demand store that does spin-on-demand, for pickup whenever you're out next, or delivery at a surcharge.

A civilized person sometimes leaves the home.

Which was already baked into the last sentence, yes. The point is that "going to a clothing store" makes no sense if we're scanning for print-on-demand anyway. The scanning and fabrication don't need to happen in the same place, and once we're in a future where products are made on demand, it definitely doesn't make sense to still have "a clothing store". That's just something that any print-on-demand store that also does fabrics can handle.

Who is going to pay $500 for a t-shirt?

You are describing many low end tailor shops. You walk in, get 3d scanned (by the 'tailor'), choose your fabrics, and the order gets sent to the printer (the nearby sweatshop). It could be same day turn around if they didn't know you would pay more to wait a week.

There are places that do that in Hoi An, Vietnam and can allegedly retain your 3d scan for custom made clothing later without needing to visit. The fashion space is full of tech innovations like that we never see or know about unless you follow the clothing industry which is not hacker new's forte by any means, gonna bet the majority is looking for hoodies and jeans here.

We should make clothing that can be reversibly fitted to many body types, can be repaired and can endure many use cycles.

Your model might be viable too though, if we use high quality yarn and knit the clothing in a way that the yarn can be respun and reused for the next piece of clothing.

Subtly paying homage to the classic Silicon Valley dress psyop [1] with the different lit photos. Cute.

[1] https://en.wikipedia.org/wiki/The_dress

How was this a psyop?

No one sees anything other than blue/black. So there are paid crisis actors out there lying about seeing other colors.

why would someone be paid to lie about the colors?

I'm being facetious in speculating how it would be a "psyop."

fwiw, i got it.

Thanks to my annoyance with the last decade plus of movie colour palettes, I saw teal and orange.

Perhaps that's the real colour scheme and the people claiming blue/black are being compensated by the conspiracy too ...

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