Charging Phones With The Power Of Paper Pulp

A disposable wireless phone charger made from molded cardboard pulp.

Here it is, the most exciting reveal since the Hackaday Prize ceremony — [Eric Strebel] uses the pulp mold he designed and built over the three previous videos. In case you missed our coverage so far, [Eric] set out to design an eco-friendly wireless charger that’s meant to be disposable after six months to a year of use, and looks good doing it.

[Eric] started by cutting up a lot of cardboard and pulping it in a brand-new Oster blender that honestly looks to be pretty heavy duty. Pulping consists of blending the cardboard bits with water until a soupy chili-like consistency is reached. That blender lasted all of 20 minutes before breaking, so [Eric] promptly replaced it with a Ninja, which was way more up to the challenge of cardboard.

To do the actual molding, [Eric] mixed his pulpy chili with ~30 L of water in a tub big enough to accommodate the long brass mold. He dipped the mold to gather a layer of pulp and pulled it, and then pressed the wireless charger in place to create a pocket for it in the final, dried piece which he later replaced with an acrylic disk of the same diameter. [Eric] points out that a part like this would probably dry within ten minutes in an industrial setting. Even though he set it on top of a food dehydrator, it still took 4-5 hours to dry. Soup’s on after the break.

This isn’t [Eric]’s first wireless charger. A few years ago, he prototyped a swiveling version in urethane foam that does portrait or landscape.

22 thoughts on “Charging Phones With The Power Of Paper Pulp

  1. So it’s meant to be thrown away after 6 months? And it destroyed a blender that should last years in the process? How is anything about that eco-friendly? Why not make one out of stuff bound for disposal and make it last many years? That’s far more eco-friendly. One last poopoo: that’s not going to last 6 months. It barely stands up. I’d give it 2 weeks and that’s generous.

    1. It might need a little more refinement in the creation stage but the concept is inherently very sound – we have reused eggbox made this way for many many years before they meet their end – usually for being covered in egg goop after breaking one… So when its sat on a desk to charge your phone it will probably last much much longer – its not holding something likely to make it die, about the only way that could happen from the phone is if its battery caught fire, and that would kill any charger… So I’d expect it to last years without misfortune, and when you do spill your morning tea on it its hardly a disaster, shake it off and don’t put any weight on it till it dries out a bit and its probably still good to use – it would take a serious soaking perhaps with extra load to really make a difference – Even thin paper I have done wet folding origami with needs a pretty hefty dose before the water really does its thing on the paper fibres – though that is quite a tricky task – it can’t be too wet as it will just become a floppy mess but you want enough wet to let you form smooth curves and really set the hard fold line solid when it dries..

      The cardboard he made it out of I would expect was already bound for disposal – with the amount of stuff he makes he is bound to get far more than enough card packaging shipped in around his supplies, know I do… So you really don’t need to buy it in specially, just a few Amazon orders, (other suppliers of stuff are available – so do use your local if it exists)…

      As for destroying a blender, you can do that with normal food use easy enough, nothing in that slurry he was pushing around or my experience with cardboard and food said tougher than commonly blended food items, so it was probably a rather crap blender in the first place…

      1. This charger is cracked along the top, every surface looks like it has been wadded up and straightened back out, the lines all meander between their vertices, and it looks rather unstable. I don’t know if you’ve used a wireless charger like this before, but you basically always have to fiddle with it a bit to find the right spot for it to charge. This thing is going to fall over, get picked up, have the folds worked to try and get it to stand up again, and then it’s going to tear along the seam lines if not just cave in on the surfaces. It won’t last. That’s why it’s claimed it will only last 6 – 12 months. A very optimistic goal. My main problem with such a claim is that something that is designed to last less than a year cannot be eco-friendly no matter what you make it out of. The energy and materials that go into producing them all pollute. Taking something made of a less or non-recycled material which is on it’s way to a landfill and using that to make something that can be thrown away is better, but making something from trash that will last far longer will have a much bigger positive impact.

        Well, I’m not sure where he or you are, but cardboard is one of the most recycled materials on earth. It should not have been on the way to disposal. It should have been on the way to recycling. Then he pulled it out of the recycling loop and made it something that gets tossed into the trash.

        Yes you can destroy a normal blender with years of use, they do tend to last more than 15-20 minutes when blending food. The only exception I’ve found is when making very thick hummus, and that blender was already years old.

        It’s really disappointing that 4 youtube videos and hackaday articles were wasted on this experiment that never should have left the work bench. All the while it’s being worked up to be something more than it is, which is a failure masquerading as a success. At least the “fail of the week” people are learning from their failures. With this disaster I’m supposed to act amazed and say how wonderful it is.

        1. Card and paper can be recycled, but this is often how it is recycled to be used are packaging – it is the exact type of project its recycled into, though probably longer lived – and at the end when it does fail its still paper pulp that can be recycled. Unfortunately a great deal of paper and card will still be disposed of as there is so much of it and recycling can only do so much with it…

        2. Oh I’d also dispute your always have to fiddle, I just drop mine on and it seats perfectly, wait a few seconds for the phone to notice perhaps but its working every time – with a design very like this one.

        1. ?? Not sure I understand what you are asking, but here’s a guess or two…

          The Foldi-One name was a joke around how much I did Origami (and paper air plane), that I liked, so it stuck if that is what you are after. Think it might have originated or been inspired by a comic strip in one of the origami books dad had, but damned if I can really remember.

          I have never quite got round to documenting anything I do, though I am seriously thinking I should and have started looking at it now, its effort to set up.

          Not sure I’ve done any wet folding for years now – the last project was roses for a friends wedding tables, loads and loads of them in purple and cream colours, those things were about the size of a tennis ball and having been wet folded really really solid. So being a wedding there must be some pictures of them somewhere, but I didn’t think to take one..

  2. Back when doing papercrete experiments I found the best small-scale pulper was a paint stirrer powered by a large electric drill in a bucket. You need something to hold the bucket down because it will want to rotate. This works much better than a blender because the speed is more appropriate for hydropulping, and you aren’t cutting paper fibers. When you’re done you simply withdraw the stirrer and you have pulp in a convenient accessible container.

    You also want to use some kind of adhesive to prevent degradation. You don’t need much. A pinch of portland cement will work for a project this size, and if you compress the pulp and time it right you’ll find that when you squeeze it the cement will stay with the pulp and the emerging water will be clean. If you use enough cement the final product will not be flammable. You can also use water soluble adhesives like PLA, which is how things like egg crates and packing inserts are made. Technically this is papier mache’.

    No matter what you do cast paper is never waterproof, but between compression and use of an adhesive it can be very durable even when it occasionally gets wet. I was planning quite seriously to build a house this way before the housing market collapsed in 2008.

  3. Yeah, I can see using that to charge my phone. There’s maybe around a megajoule of energy in that material — throw it on the conveyor feeding a coal power plant and you might get a hundred watt-hours of electricity out of it — enough to charge a phone once or twice, with the hideous efficiency of wireless charging.

    Don’t believe Qi’s claim of 80%, or even the independent folks saying it’s 60%. Measure it yourself. I did. A 5 watt-hour charge per day into my phone took 35 watt-hours per day from the wall plug. 14% efficiency. Much of that is just standby losses, but the charger still draws 12 watts from the wall to charge the phone at the rate of a lousy 3 watts.

    Seriously, if you want to do good for the environment, don’t use wireless chargers, eco-pulp or not.

    1. With good alignment and close coils wireless is pretty good efficiency wise, obviously still not on par with wired but its not bad, the fact it can still work when you have lousy alignment, or a big chunky phone case separating the coils at lower efficiency is basically just user error.

      When you then consider how many of these devices fail because the charge port is busted, or it lets in water, or the weak point in the case to accommodate the cable leads to it breaking something else – there are a great many common failures wireless charging prevents or reduces, so as long as everyone will actually keep a still working device longer than the 6 months for the next shiny model with the iterated number on the end to be available that is actually a big environmental win – the devices in construction consume more energy than they will through many years of use – so not having as many broken ones saves much more energy than is lost by wireless charging.

  4. If this was meant for a one-off prototype, then [Eric Strebel] made a much nicer and presentable looking one out of cardboard in his previous video. An even nicer looking (and probably sturdier) one could have been spat out of his FDM printer, which he instead used to print a former for his mesh pulp mould.
    This pulp moulding process doesn’t even appear to be useful for mass-production, unless multiple moulds can be put aside for multi-hour drying step to complete before demoulding.

  5. Speaking of “disposal”, I have an old garbage disposal in the garage.
    The motor and blade is still good, but it became blocked when corroding metal (zinc?) squeezed the plastic drain tube closed.
    It might be useful for such a shredding procedure.

  6. This may seem like a stupid question, but why not place the phone directly on the charging hardware, with no stand? Isn’t that the most eco friendly? Secondly, if you had to have a stand, why not cardboard? It can still be recycled cardboard, but you make a much sturdier stand with folded carboard.

  7. What in the heck is “eco friendly” about throw away anything?

    This is a device that is intended to be thrown away after 6 months to one year – then you throw it away and buy a new one.

    What’s going to change in those 6 months that makes the old stand incompatible with the phone or the charger? Nothing. Why throw away that stand after 6 months? Damifino.


    We’ve got too much “throw away” stuff now as it is. None of that stuff is classified as “eco friendly.”

    It’s a waste to throw stuff away just so you can buy a new one.

    Some things it’s kind of unavoidable – I’m sure I don’t want a doctor re-using tongue depressers on different patients.

    Designing everyday objects to be disposable rather than durable is just stupid, though.

  8. Die cut and folded cardboard would be sturdier and look much nicer. Could even be cut from clean, post-consumer cardboard.

    Recycling in paper is often BS. Paper factories have *always* done recycling. Rough edge trimmings, end cuts, when the web tears they cut the ends square and the “broke” pieces go back into the pulp vat with all the other trimmings. Ideally the plant will be running the same type/color of paper so it can be run through again with no effect on the product. Or if it’s trimmings and broke white paper it can be tossed in any time a batch of white is being run.

    Small amounts of color paper waste can get tossed in with unbleached for cardboard or pulp egg cartons. How commercially made screen formed pulp products like egg cartons and cup holders gets dried fast is excess water is drawn from the pulp through the screen molds with vacuum.

    For real paper recycling the only number that matters is how much is “post consumer”. If you buy white paper with any post consumer content it’s most likely made from paper that required extra bleaching and detergents to remove inks and stains, so that’s more chemicals used than paper made from unrecycled wood pulp.

  9. Just found this Japanese designer 3D printed mold, looking for easier way to design the paper pulp mold :
    It also have the mesh that allows quick drying, and you won’t struggle hours welding brass mesh. It is modular, and you can easily print several identical molds.
    As I’m looking for a way to “eco-friendly” and sefely ship my fragile products to customers with very small series (10 pieces), it’s the best I could find so far.

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