General / Off-Topic Would a suction cup work in space?

[YoBuck]

A question a friend of mine asked a while back. We kind of nailed down an answer but it made for a good chat.
So.

Would a suction cup work in space?

 

[Kopachris]

Not in a vacuum, but it would in an atmosphere in microgravity (e.g. on a space station).

 

[YoBuck]

Does a vacume affect a suction cup?

Lets ta say this suction cup is in deep space, with a nice pane of glass to get all sucky on.

 

[YinYin]

Yes, it works via pressure difference. Without atmosphere you can't achieve that.

 

[Zenith]

Inside a ship or station, no problem. As long as you have an atmosphere then suction will work fine.
Outside a ship in open space, nope. Space will always be a better vacuum than a suction cup could achieve.

 

[YoBuck]

Yes, it works via pressure difference. Without atmosphere you can't achieve that.

You're not thinking it through yet.

 

[YinYin]

You're not thinking it through yet.

Maybe we are thinking of different things. But a suction cup is essentially pressed against whatever surface it engulfs a 'vacuum' with by the outer higher pressure.
Much like any suction process is actually a push from the gas opposing the created vacuum.

 

[YoBuck]

Inside a ship or station, no problem. As long as you have an atmosphere then suction will work fine.
Outside a ship in open space, nope. Space will always be a better vacuum than a suction cup could achieve.

is there any way I could manufacture a suction cup from a memory metal say?
what I'm saying is there are other ways a suction cup works. So far we are all hitting on the ideas me and my mate talked about, but there's more to a suction cup than just pressure...

 

[YinYin]

Enlighten us then

 

[YoBuck]

The way I understand it after much thought and asking around is a suction cup works via pressure difference in an atmosphere or I the lack of one the mechanical forces of a suction cup take over.

This is ain't a diffinitive answer as I'm not a mathematician so can't prove it. But that's how I understand it.

 

[Fenris Wolf]

but there's more to a suction cup than just pressure...

Nope, there isn't.

https://en.wikipedia.org/wiki/Suction_cup

 

[YinYin]

Mechancial 'forces' could only mean 'hooks' of any shape or size (actually grabbing imperfections on the surface). Without those or pressure differences it will never hold.

Suction cups don't have those - but some fancy animals do.

 

[Fenris Wolf]

Or if you want to watch an explanation rather than read one...

[video=youtube;BPF7uI2rujY]https://www.youtube.com/watch?v=BPF7uI2rujY[/video]

 

[YoBuck]

Mechancial 'forces' could only mean 'hooks' of any shape or size (actually grabbing imperfections on the surface). Without those or pressure differences it will never hold.

Of corse, like a flexible disc could become stuck via suction but not mechanical forces. That's not a suction cup though. A suction cup by shape grips and tries to pull back to its original shape so that's a pure mechanical force like a memory metal. Although I'm not sure memory metal is a good analogy

 

[YinYin]

Either way, suction cups don't generally provide that as they are made to work with pressure and thus require as little imperfection/hooks as possible.

If you are going for hooks it's not a suction cup anymore.

edit: this stuff would work: https://en.wikipedia.org/wiki/Synthetic_setae

 

[sbdags]

Of corse, like a flexible disc could become stuck via suction but not mechanical forces. That's not a suction cup though. A suction cup by shape grips and tries to pull back to its original shape so that's a pure mechanical force like a memory metal. Although I'm not sure memory metal is a good analogy

You seem to be ignoring the laws of physics. Suckers work on pressure. Nothing else. No atmospheric pressure difference then no suction.

 

[ianw]

Do we know anyone on the ISS that can test it?

 

[YoBuck]

edit: this stuff would work: https://en.wikipedia.org/wiki/Synthetic_setae

ah good find I never equated it to this. Science stuff interests me, I only have the basics but the foot thing is what I was getting at.
On the small scale a pool ball is less uniform that the earth with all its mountains and oceans so the "grip" is already on most surfaces at that level right

 

[YinYin]

ah good find I never equated it to this. Science stuff interests me, I only have the basics but the foot thing is what I was getting at.
On the small scale a pool ball is less uniform that the earth with all its mountains and oceans so the "grip" is already on most surfaces at that level right

Yup, these nano structured surfaces working at van der waals levels can basically grab onto any surface (lest it is very porous and thus doesn't provide enough actual surface).