The videos are great, consumes a lot less water than I imagined. Seems like most of the water is lost during the de-suction process, if they can scavenge that it could really cut the water consumption down nearly to zero.
My understanding of it after a quick read of the paper: you want to make a suction cup. The usual way is with a solid cup (think plastic) with a softer rubber-like ring around it. Near the ring, you will have atmospheric pressure (high) outside, and vacuum pressure (low) inside, so if the ring doesn't make perfect contact with the surface, some air is going to come in and ruin you vacuum. What they are doing is that they are rotating a bit of water in the suction cup, which because of centrifugal force will come close to the suction cup frontier in a ring-like shape. This water ring will -- thanks to fluid mechanics black magic -- have a different pressure at its exterior and its interior. Its interior pressure will necessarily be the same as the vacuum, and you can make it so that the pressure outside is the same as the atmospheric pressure, hence, according to this paper, if the rubber ring fails to make hermetic contact, air won't come in because at the frontier of the cup, the pressure is the same both outside (atmosphere) and inside (exterior of the water ring).
Does the water on the innermost edge of the rotating ring, which is exposed to the vacuum, NOT vaporize because the absolute pressure is still above 10kPa (100kPa atmospheric - 80kPa vacuum)? [0]
Will the seal slowly evaporate away or absorb into a porous surface like concrete?
The patent won’t hold. We have prior art from alien spacecraft for decades now.
Most of our current propulsion and lift mechanisms are based on momentum transfer, which has many problems in air. His work makes me think there are a lot more efficient mechanisms to be discovered.
Kind of similar to the reason you'd wet a suction cup before using it: the water helps plug any small air gaps. But in this version, a fan spins the water and air inside the cup, with the heavier water being forced to the edge, and any water leakage being replaced from a reservoir.
Whereas the suction cups in the article, use spinning water as a way to seal suction cups on rough surfaces (the water fills in crevices of rough surfaces I presume, allowing the suction cup to seal). The water is also spinning (i.e. it has an inertial force) so that it counteracts the vacuum pressure in the center of the suction cup.
What about ferromagnetic fluid? You can still spin it if you are aiming to push it 'centrifugally' into the features of the vacuum boundary, but you shouldn't lose a lot during the detachment.
No idea if this is actually a new idea but it's definitely new to me and I love seeing it. What a cool concept, likely to be a few applications in industry beyond spiderbots.
[+] [-] czr|6 years ago|reply
video 1 (response measurement): https://aip.scitation.org/doi/suppl/10.1063/1.5129958/suppl_...
video 2 (picking up block): https://aip.scitation.org/doi/suppl/10.1063/1.5129958/suppl_...
video 3 (hexapod): https://aip.scitation.org/doi/suppl/10.1063/1.5129958/suppl_...
video 4 (human climbing tiled wall): https://aip.scitation.org/doi/suppl/10.1063/1.5129958/suppl_...
video 5 (human climbing concrete wall): https://aip.scitation.org/doi/suppl/10.1063/1.5129958/suppl_...
[+] [-] keanzu|6 years ago|reply
[+] [-] logicallee|6 years ago|reply
[+] [-] NougatRillettes|6 years ago|reply
[+] [-] thebiss|6 years ago|reply
Will the seal slowly evaporate away or absorb into a porous surface like concrete?
[0] https://en.m.wikipedia.org/wiki/File:Phase_diagram_of_water....
[+] [-] ta1234567890|6 years ago|reply
Some more info: http://sciencechatforum.com/viewtopic.php?nomobile=1&f=77&t=...
I believe he has a couple of patents on the technology, but not sure he'll ever get around to making something practical with it.
[+] [-] war1025|6 years ago|reply
I watched multiple of the videos he has listed and from what I can tell the phenomenon he is demonstrating is real and reproducible.
Whether or not he's crazy, who's to say?
[+] [-] NougatRillettes|6 years ago|reply
[+] [-] jl2718|6 years ago|reply
Most of our current propulsion and lift mechanisms are based on momentum transfer, which has many problems in air. His work makes me think there are a lot more efficient mechanisms to be discovered.
[+] [-] raihansaputra|6 years ago|reply
https://aip.scitation.org/na101/home/literatum/publisher/aip...
https://aip.scitation.org/na101/home/literatum/publisher/aip...
(from the actual paper link from czr: https://aip.scitation.org/doi/10.1063/1.5129958)
[+] [-] Iv|6 years ago|reply
One way of explaining it would be that instead of leaking air, it leaks sealing water without suffering dpressurization in the process. Really neat.
[+] [-] flashman|6 years ago|reply
[+] [-] catalogia|6 years ago|reply
[+] [-] Rury|6 years ago|reply
Whereas the suction cups in the article, use spinning water as a way to seal suction cups on rough surfaces (the water fills in crevices of rough surfaces I presume, allowing the suction cup to seal). The water is also spinning (i.e. it has an inertial force) so that it counteracts the vacuum pressure in the center of the suction cup.
[+] [-] AliAdams|6 years ago|reply
(Plus it looks much more sci-fi.)
[+] [-] ambyra|6 years ago|reply
I wonder if some sort of jelly would work to do the same thing, like a snail. Or a dynamic cup surface that conforms to the wall better.
[+] [-] jcims|6 years ago|reply
[+] [-] Terr_|6 years ago|reply
Sounds like a "momentum transfer" vacuum pump, shaped so that the output side bleeds out along the rim.
https://en.wikipedia.org/wiki/Vacuum_pump#Momentum_transfer_...
[+] [-] jakedata|6 years ago|reply
[+] [-] rusttoxic|6 years ago|reply
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