Aquaporins. In simple terms, these are water channels in the cell wall that allow for H2O molecules to travel in and out of the cell so that the cell won’t swell and explode. Scientists discovered that by using these aquaporins, you can sort out H2O molecules from otherwise impure water. Aquaporins themselves are very small and delicate, so a screen is used and the aquaporins are melted onto the layer of net. Impure water can then be sifted.
Right now this technique is generally used in industry because it provides ultrapure water. Ultrapure water is so clean that the taste is repulsive. It doesn’t have the nutrients and minerals in tap water so it can be shocking to taste, but it works great for cleaning or soaking machinery for big companies.
“Aquaporins are selective membrane channel proteins found in the lipid bilayer of living cells that work to transport water across the cell membrane. Aquaporins accomplish this task while excluding any unwanted ions or other polar molecules, making them a perfect model for the formulation of low-energy water filtration systems” (The Biomimicry Institute, 2016).
Aquaporins have a bright future for desalinating seawater. But wait! If these aquaporins are great at filtering water, why aren’t they in use right now? Developing countries could really use a simple technology like this with a good efficiency and low cost. According to Professor Peter Agre at John Hopkins University, “The engineering of this will have some technical difficulties because the native membranes are very tiny and so only nano-water purification can occur”. The sensitive membrane can only handle a few drops of water at a time. Read more on nanofiltration here.