What's missing here is any evidence that the same cool parachutes will work on anything of significant mass, e.g. a parcel weighing 2kg or an average human weighing 80kg.
It looks like adding flexible ailerons or whatever they'd be called could give a big advantage in precision landing, with slower forward/sideways speeds but much better control.
Making it modular, with interlocking but separate parts, might make great sense for repairability and safety for skydiving? From the little I know of the sport, things tend to fail catastrophically, going from perfect condition to total disaster without a whole lot of graduated steps in between. I also wonder if there's some utility in paramotoring - multiple kirigami stabilizers, maybe, with a central parafoil, or one big kirigami rig with the fan blowing straight up its skirt?
This is awesome research. Paper drone-delivery parachutes are definitely a use case, but maybe some of the more dangerous flying sports could be made much safer, as well.
edit: Apparently no, 100 meter radius kirigami chute would be needed for a single person parachute, not exactly practical. Apparently it's just really, really good at ensuring things drop straight down with a lot of drag.
Apparently the electric field is till quite strong some way from the surface.
It looks like it depends on the stiffness of the material (paper), so scaling it up to human (or bigger) sized will come with "interesting" challenges :(
https://www.coopoly.ca/p-545851-bouteille-noire-thermos-510m...
Note also the extra weight attached by the researchers to its bottom
(This is not yet taking into account the data-based scaling formulae presented in the paper)
>Baby spiders use "ballooning" -- a single thread -- to fall so slowly that they can travel far in thermal updrafts.
Gary was one of the TAs in the class. The non-reducibility of letterforms has remained a fascination—I always did like the (computational) linguistics corner of cognitive science!
One answer is a dandelion seed. Not exactly the same, but a dandelion seed is about 85%+ "porous" - the pores here being the space between the spindles, not actual holes per se. And it turns out that high porosity is critical to stabilizing the wake turbulence not unlike what is described in the Nature video. https://sites.nd.edu/biomechanics-in-the-wild/2021/06/01/inn...
A learning that kirigami parachute researches might apply: The dandelion pappus is less porous near the center and becomes more porous toward the outer edge. A lower porosity near the central hub can increase shear flow, helping to detach and strengthen the vortex
Furthermore, spiders which have been known to "balloon" on the wind even across entire oceans use multiple strands of silk which are negatively charged to repel each other, thus forming some of the same gaps that are seen in a dandelion pappus, with similar aerodynamic benefits. https://journals.aps.org/pre/abstract/10.1103/PhysRevE.105.0...
> As well as kirigami, the team drew inspiration from nature. Instead of relying on a gliding angle, many wind-dispersed seeds are equipped with structures that stabilize the airflow around them: including the feathery bristles of dandelion seeds, which create a stabilized vortex in their wake.Krigami is about folding and cutting - this looks like cutting only, though it kind of folds due to air drag
Also I bet they really need people who can help with the simulations. If you email the authors you can probably get added to the team.
I too love this. It’s that intersection of devilishly hard and almost useless unless you squint then it’s sci-fi magic tech. There are quite a few cases where you want the parachute to drop straight down.
Model rocketry, for example. You don't want your rocket to drift miles on its chute. However this is mostly solved by 2 stage deploy (drogue deployed at apogee, then full size chute deployed near ground).
I could't help but roll my eyes at this textbook example of describing new technology as being "useful for humanitarian or search & rescue work", instead of the much more obvious usefulness in military applications.
Who's kidding who about what "precisely targeted airdrops" are most likely to be used for? These will be in use by Ukraine well before anything beyond a technology demo drops on to a "stranded hiker" in a National Park...
Retarded bombs are slowed with a variety of mechanisms, from spring-loaded airbrakes to inflatable ballutes to parachutes. Fuzing can range from superquick for conventional bombs to extended timers for nuclear weapons, all depending upon the application. These parachutes would be great for low flying drone bombers as well as munitions that are highly attitude-sensitive (such as those with improvised fuzes).
Bombs go down fast, specially from drones, there's no advantage in slowing them down.
I've seen this so many times now. Is there a established Internet meme for it yet?
Dropping supplies to isolated or behind-the-lines forces is a very real logistical issue. While some of those supplies might be munitions, rations and medical supplies are a significant part of the need.
I know, it doesn't make you feel any friendlier to the issue, but tech has multiple applications. Chainsaws were invented to increase survivability of mothers in difficult births.
However it isn't clear that these would be any better than conventional parachutes.
Secondarily, slowing the weapon can be useful for low flying platforms. Retarded bombs use spring-loaded airbrakes, inflatable ballutes, and/or parachutes to slow the weapon enough to allow the bomber to escape damage.
https://youtu.be/dcsf5yuEHDY?t=69
https://forum.cartridgecollectors.org/t/drone-dropped-anti-t...
On the second pipe you can also see small fan which probably arms the side attached detonator.
Only if you don't price in all the externalities: loss of delivery jobs, environmental cost of the drones, cost of drones hitting people, cars, buildings and powerlines etc.
Like if you switch from a low quality butcher to a higher quality butcher, you are not imposing a cost on the lower quality butcher.
You can not like it as a consequence of course, whether it is an externality or not.
Replacing 3 delivery guys with 1 drone maintenance guy imposes a cost on society if those delivery guys can't then find work.
Nothing much has changed about precision in delivery of goods.
I can imagine how meaningful it would be if one day these kirigami parachutes are used to drop medical supplies, support disaster relief, or even serve space missions. Beautiful and practical at the same time.
I can think of one place that would have IMMEDIATE utility.
What an achievement for such a simple and elegant solution, bravo!
[1] Kirigami-inspired parachutes with programmable reconfiguration:
To whoever is running the simulation: This is a bit on the nose. And don't even try to Baader-Meinhof me.
But the I took an arrow to the knee.
This is a funny timing. I was just discussing with my son this morning what the most efficient ways were to set free the mice we catch in our mouse friendly trap. One of the "options" we came up with was a launching mechanism and a tiny parachute to send them to a field at the end of our street. The main problem we came up with was that it was really hard to predict where the mouse would land. I'll show him this kirigami design this afternoon :-)
(Disclaimer: obviously we're not actually launching mice. These are just thought experiments. I actually walk to the field to release the mice.)
ugh123•4mo ago