Artificial gills are a bad idea?

[liberato]

We commonly call air "O2"...

I agree with the rest of what you said but I have never heard of normal air called "O2" by anyone.

In any case, Bodner's invention has never worked and never will (as a self-contained diver apparatus) until there is a portable power source way, way beyond what we currently have. So, until dithithium crystals become commonplace it is just a scam looking for investors.

 

[lowwall]

There was an article in New Scientist on this in the last year.

http://www.lacoctelera.com/myfiles/artedi/Breathing in oceans.pdf

Bodner's approach is covered and essentially dismissed. More interesting are membrane approaches.

"Making a crude artificial gill is surprisingly easy. All you need is a watertight box made out of a membrane that is highly permeable to gas. Fill it with air and put it underwater and you've got a gill. The levels of oxygen and CO2 dissolved in water are in equilibrium with the atmosphere above it, so diffusion through the membrane will result in concentrations close to those of the atmosphere inside the box."

Using membranes various inventors managed to keep a hamster alive in 1961, a small dog in 1980, and eventually a human. Only problem with the final version was it's slightly excessive size (it's the yellow and black box the diver is hanging onto):