If you have a fear of heights and find yourself falling out of an airplane, you probably don’t want to look up to find your parachute full of holes. However, if the designer took inspiration from kirigami in the same way researchers have, you may be in better shape than you would think. This is because properly designed kirigami can function as a simple and effective parachute.
Kirigami, for those unfamiliar, is a cousin of origami where, instead of folding, you cut slits into paper. In this case, the paper effectively folds itself after being dropped, which allows the structure to create drag in ways similar to traditional parachute designs. Importantly, however, the stereotypical designs of parachutes have some more severe drawbacks than they appear. Some major issues include more obvious things, such as having to fold and unpack before and after dropping. What may be less obvious are the large eddies that traditional parachutes create or their ease at being disturbed by the surrounding wind.
The kirigami chutes fix these issues while being easier to manufacture and apply. While these are not likely to be quite as effective for human skydiving, more durable applications may benefit. Quoted applications, including drone delivery or disaster relief, worry more about accuracy and scalability rather than the fragile bones of its passenger.
Clever and simple designs are always fun to try to apply to your own projects, so if you want to have your own hand, make sure to check out the paper itself here. For those more interested in clever drone design to take inspiration from, look no further than this maple seed-inspired drone.
Reminds me of the Ribbon Chute from MDK, I wonder if this could be made similarly rapid-stowable? Maybe even making the disc inflatable so that when it’s deflated, it’s super soft and could be haphazardly stuffed away/yoinked in by cable reels, then inflated again on deployment so that it’s stiff enough to hold its shape?
Whoa… haven’t thought of that game in years. I bet small ram air scoops along the outer edges might force enough in to make it inflate.
Don’t parachutes generally already have slits or holes in them?
Yes. A “normal” round parachute has a hole in the top to allow the air to get out and stop escaping from the sides thus rocking the object attached and at a point collapsing the canopy and crashing the load.
The lateral slit is used to control the direction the parachute glides. You basically get a jet propulsion forward and you can stere. Is/was used for sport and perhaps in the military, but it may have been surpassed by the rectangle parachute, which is more controlable by deforming the sides using the strings attached.
You also have the paraglider, which is full of holes, better said tubes, that are filled by the incoming air and becomes a kind of a fixed wing with all the benefits and downsides. Also if it colapses (the air escapes from the tubes and those are not filling back up because it gets “crumpled”) you won’t have time to complain about what is coming to you. That would be the Earth.
To end with an anectode: the most difficult jump is not the first, but the second. Cos’ you know what’s about to happen.
Paragliders will usually re-inflate very quickly after collapses. 20 years ago you had to choose between safety and performance, now many contest will not even allow you to fly except with the two highest safety classes as they have become performant enough!
Some model rockets use a streamer instead of a parachute. Anything with drag will work if sized so the drag is sufficient.
At one point I had a set of model rockets with different recovery techniques: parachute, streamer, tumble, featherweight. Never got around to building a glider.
Did you tried the airbag method, used on the Mars rovers? At a precomputed height, lots of airbags get inflated around the object (still dragging besides the parachute) and when very close to landing surface (tens of meters) the parachute is cut and the object jumps around while the gas leaks slowly from the airbags thus reducing the elastic coeficient and reduces the back jumps until the object settles. It may have a prefered order of deflating so the object lands upright.
Explosive?
I know, not really a recovery technique.
I will never forget my horror watching my hobby rocket parachute deploy perfectly, dangling a burning fuselage below it. I had bought the largest engine I legally could given my age. It did not start a fire but it was really close to drifting onto houses close by the park.
But you can’t control it. You can’t drop it any other way than just like a bomb downwards. Not like a paratrooper who can choose where to land.
This has been a topic on the model rocketry forums. The lack of drift is a real feature in that hobby — and in other applications. Perhaps multiple, stacked chutes might provide additional drag. This is science at its beginning; lots that can be done.
Perfect parachute for a dense atmosphere like on Titan or Venus. Light in weight and easy to stow makes it perfect for a space mission. Due to Venus’s high temperature and corrosive extremely dense atmosphere a titanium mesh Kirigami parachute would lower a probe to surface while saving weight.
Wow these are like the 711 fabric cup holders, at least in Asia!
I love this idea. Simple, effective and cheap, kinda hard to beat that combo. I wonder if conductive fabric could make the “flaps” somewhat adjustable via EM. Also, unless they’re starting a cult to worship parachutes, “holey”.