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Giant Plastic Lung... Answered

I have made a giant lung out of polythene plastic and I want it to inflate and deflate by itself, on a loop, inside a small room. How do I make this happen? I have access to power sources, plugs etc. I don't have a lot of money

I am looking at breathing, it is there but doesn’t have a form. I am making breath something that can be caught by making a lung that I have built out of plastic.



4 weeks ago

The usual way is to enclose the bag in a vessel and suck out the air. Allowing normal pressure air to inflate the "lung"

You need something that has high volume rather than high pressure - as suggested bellows could work.

Jack A Lopezrickharris

Reply 4 weeks ago

The usual way? Do you mean to say this thing is an example of an art you have seen before?

What search words should I be using to find typical, usual, examples of this art?

Is this, "model lungs in a jar?"


Come to think of it, I think I have seen that trick before, in pictures, if not in real life.

I dunno. I think the thing in OP's picture is going to need a really big jar.

rickharrisJack A Lopez

Reply 20 days ago

It's a demonstration you often see in school science labs. ;-) The picture tells it all.

Wouldn't be hard to make an acrylic enclousure - It wouldn't need much vac to inflate a poly bag.


4 weeks ago

Ever seen a blacksmith working? ;)
Put a hinge on the ends of two wooden boards.
Glue your "lung" to them.
Opening and closing the boards makes your lung breathe....

Jack A Lopez

4 weeks ago

What, in the second picture, is the white thing with a white cord trailing away to the bottom right?

Is that some kind of electric air blower?

It kind of made me wonder about what is the best way to reverse the flow from a pump that only pushes one way.

There is a kind of valve, often used with hydraulic fluid, with a spool-shaped piece in it, used for reversing the flow from a pump that only pumps fluid in one direction.

This page, at mathworks,


has the clearest illustration I could find

I was thinking this illustration could serve as inspiration for building such a valve, for use with blowing air.

Although there might be an easier way. Like, if you could find an air blower that was truly reversible, in an easy way; e.g. just by changing the direction of rotation of a motor.