The Science in the Breathing Membrane of "Once Humans"
[image error]Why can’t we breath under water the way fish do? They need oxygen just as we do. Fish, though, don’t breath the oxygen in the water molecule (H2O), they breath the free oxygen that’s dissolved into water. And the waters of our lakes and oceans contain plenty of it.
Newborn mammals can survive in water for long periods of time. Newborn rats submerged in water at 37 degrees continue to make respiratory movements, can survive underwater for at least 40 minutes, recover when taken out of water, and develop normally into adult rats.
The ability of newborn mammals to survive in an aquatic environment is partly explained by their tolerance to anoxia. In principle, the administration of the necessary enzymes to adult mammals could restore this initial tolerance to hypoxia. On the other side, If you want to kill a fish, just put it in water that’s been boiled for some time, then cooled without exposing it to air. Dissolved oxygen will’ve been driven out through boiling, carried away by steam bubbles. If you put now a fish in the water, since fish do not extract oxygen from the H2O, it’ll suffocate.
According to Henry’s law, the mass of a dissolved gas in a given volume of solvent at equilibrium is proportional to the partial pressure of the gas on the gas-liquid interface. The consequences of Henry’s Law are fairly straight forward. Double the pressure, double the concentration (mole fraction) of dissolved gas.[image error]
A common measurement often taken is the amount of dissolved oxygen (DO), which is a measure of how much oxygen is dissolved in the water – DO can tell us a lot about water quality. The oxygen dissolved in lakes, rivers, and oceans is crucial for the organisms and creatures living in it.
At atmospheric pressure, a small amount of oxygen, up to about ten molecules of oxygen per million of water, is dissolved in water. Oxygen enters a stream mainly from the atmosphere and, in areas where ground-water discharge into streams is a large portion of streamflow, from groundwater discharge. Rapidly moving water, such as in a mountain stream or large river, tends to contain a lot of dissolved oxygen, whereas stagnant water contains less, and cold water can hold more dissolved oxygen than warm water.
Medical technology has produced ‘artificial lungs’ in which the blood of a patient is made to flow in the artificial device and be oxygenated in a process similar to what happens in gills. A gas exchange modelled after the gills of a fish could enable humans with liquid filled lungs to obtain the necessary oxygen from sea water.
The body must also eliminate carbon dioxide. Without this ability the blood’s acidity wound increase and damage occur. Silicone rubber gas-exchange membranes can absorb carbon dioxide and match the CO2 elimination rate which the human body needs.
Fish gills include feathery structure membranes that offer a large area capable to deal with a great amount of water flow. As water passes through, dissolved oxygen flows into the membranes just as it flows into the membranes of our lungs. People working on artificial gills are developing techniques for processing the gas that crosses the membrane to make it more oxygen-rich. There is another problem, though. Very little nitrogen dissolves in water. Without it, pure oxygen becomes toxic at pressures thirty feet below the surface. Even with an artificial gill, a diver would still need nitrogen.
Gill membranes not only acquire new oxygen; they also scrub out CO2. If the system could also provide the required amount of nitrogen, we could spend indefinite time under water.
So far, a truly breathable membrane is still in the realm of science fiction but researchers know what to look for and what the desired goal is. In Once Humans: Daimones Trilogy, Vol.2
we encounter such technological exploit,
I undressed and entered the water room; the bluish fluid globe rotated slowly in the middle. I put on a breathing membrane and waited for it to mold to my face before entering the globe and shutting the world out.
The membrane also enhances Dan’s ability to breath by penetrating the skin and delivering oxygen directly to the brain. The membrane also operate to cause a breakdown of the blood–brain barrier, thus opening an additional way to supply the brain with oxygen enriched blood.
No doubt we will see artificial gills work in reality sometime in the future, but I honestly cannot see them becoming popular in sports diving in my lifetime!
The post The Science in the Breathing Membrane of "Once Humans" appeared first on § Author Massimo Marino.
