[Update May 8 2016] After it raised over $600K, Indigogo have suspended the Triton 'artificial gills' campaign and refunded all the contrbutions, issuing the following statement: Discussed in this thread starting here. -------------------------------------------------------------------------- Original Post follows: Claim: Currently trending on Indiegogo is a campaign for an 'artificial gills' product called Triton: https://www.indiegogo.com/projects/triton-world-s-first-artificial-gills-re-breather#/ At time of writing, this has attracted over 1,400 backers and over half a million US$. The campaign claims: "Triton. A state-of-the-art oxygen respirator, that allows you to breathe underwater by utilizing our ‘artificial gills’ technology. Swim among tropical fish, marvel at exotic coral and experience the serene beauty of marine life − without having to come up for air" The device is claimed to "extract enough oxygen for a human to comfortably breathe underwater", by extracting dissolved oxygen from water using "Microporous Hollow Fiber. This is the pioneering technology that keeps water molecules out, and lets oxygen in", powered by a "modified lithium-ion battery" running a "modified micro compressor". Use in seawater is explicitly stated to be OK. Product photos and a short video are offered as evidence. They claim to have a working prototype. History: Some people may remember the design from a viral 'news' item from couple of years ago. This was widely reported, including on reputable news sites, as if it was a real thing, however it eventually emerged that it was in fact purely a mock-up concept design produced by a student. The concept was explained to be so impractical as to be effectively impossible by a few people at the time. Now the design is back, this time apparently for sale. The uncritical previous news reports are the source of the 'quotes' on the indegogo page. Debunk: The device shown cannot work as described (and even if it did, it would be extremely dangerous), there is simply too little dissolved gas in water to allow the principle to work in any practical way. The video presented is fake. There is no working prototype. Evidence that the device cannot work as described:Note that the device is specifically claimed to allow a person to breathe comfortably, NOT that it performs any other more obscure actions to deliver metabolically required O2 and remove CO2 from the body. Human adults have a lung tidal volume (the volume of air you breathe in and out each breath) of about 500ml. . Adult divers in a relaxed state will breathe a total of very roughly 15 litres of gas in aggregate every minute at the surface. This increases with exertion. If tidal volume is restricted, humans become unable to effectively flush CO2 produced by metabolic activity from the lungs and will become hypercapnic, quickly leading to distress and death. Sea water contains very roughly 6ml of dissolved oxygen gas and 12ml of dissolved nitrogen gas per litre, at 15 degrees C (60 degrees F).  . Less in warmer water. So the device would have to process around 27 litres (7 gallons) of seawater to extract enough dissolved gas to allow an adult to take a single breath, at the surface, assuming perfect efficiency. It would have to process 800 litres (28 cubic feet) of seawater to allow an adult to breathe for one minute at the surface. This is the approximate flow rate of twenty garden hoses or one fire hose through the device. Flow rate would have to increase with increased exertion, warmer water, reduced efficiency or increased depth. At the 15 feet max depth claimed for the device, in tropical water with mild exertion and a generous 50% efficiency this could quickly become 4,000 litres per minute, or the flow rate of five fire hoses. (Powered by a device the size of a mobile phone...) The thrust that this produced would move a diver rapidly and uncontrollably, if they could even retain it in their mouth (do ask a fireman to hold their fire hose in their teeth...) This is giving the benefit of the doubt that the device can extract both oxygen and nitrogen (...and no other dissolved substances such as carbon dioxide, chlorine or pollutants) from the water to allow a person to breathe. If it really is just to extract oxygen as it states on the web page, then the above calculations of flow rate need to be tripled. Evidence for fake video: The diver in the presented video shows no sign of being moved by the force of multiple fire hoses of water processed through the device. Although the diver appears to be producing bubbles at intervals, the volume of bubbles each time is tiny compared to a full exhale. He is noticeably buoyant (having difficulty staying submerged) at the start of the video, and becomes neutrally buoyant towards the end. The explanation for this is that he took a full breath before the start of the video, and is letting it out in short bursts, NOT breathing from the device. He becomes less buoyant as his lungs empty. The entire video is shorter than the length of an un-challenging breath hold. Evidence for dangerous: Humans cannot detect when the gas they are breathing becomes hypoxic. (Pilots train for this in case of depressurisation, and this is why airlines advise you to put your own mask on before helping others. The urge to breathe is driven by rising CO2, not falling O2 levels.) If a diver using this device moved into an area of water depleted of oxygen, they would have no way of detecting it until they fell unconscious from hypoxia (which is not a good thing underwater). Once water had been processed through the device it would be depleted of dissolved gas so a diver would have to constantly move in search of fresh water, without any way of knowing where that might be. So how do fish manage this trick with gills? Simple answer - they are cold blooded, require a tiny fraction of the oxygen we warm-blooded mammals require for metabolism, and can remove CO2 from their bodies also using their gills, not lung ventilation. Final note that the Indegogo page specifically places the responsibility for due diligence on to backers; it also states that the project will recieve all funds even if it does not reach all goals. Caveat emptor. Another couple of debunks of the concept along similar lines: http://www.deepseanews.com/2014/01/triton-not-dive-or-dive-not-there-is-no-triton/ http://www.nigelhewitt.co.uk/diving/rant/index.html#gills  https://en.wikipedia.org/wiki/Tidal_volume  http://www.engineeringtoolbox.com/oxygen-solubility-water-d_841.html  http://www.waterencyclopedia.com/Re-St/Sea-Water-Gases-in.html [UPDATE: 4/1/2016] So, to recap, not only have "Triton" debunked their own claim (the previous claim was clearly that the artificial gills themselves allowed a person to breathe comfortably, no mention of single use consumeable canisters), but they have doubled down on bizarre claims (liquid oxygen!), and a new video already debunked as fake with a hidden air tube. For another factual debunk of the latest permutation of the claim, we can calculate the volume of liquid oxygen that would be required to allow a human to breathe for 45 minutes. Firstly remember that the volume of gas required to "allow a human to breathe comfortably" is in the region of 15 litres a minute (driven by the need to flush CO2 from the lungs). Over 45 minutes, that totals to 675 litres. The expansion ratio of liquid oxygen to oxygen gas at one atmosphere pressure is 1:861, so you would need just under 0.78 litres of LOx to create 675 litres of oxygen gas. The brand new campaign page claims the canisters are useable for two 45 minute dives, so double the LOx to 1.6 litres. The triton page gives the dimensions of the device as 29cm x 12cm. It doesn't give a height, but 4cm might be reasonable, given that it easily fits between the nose and chin of the subject in the video. That gives a total envelope volume of roughly 1,400 cubic centimetres or 1.4 litres. The device itself is much smaller than the total envelope, as most of the length is taken up by the 'gills' part of the design which are slim tubes. So you'd need a volume of liquid oxygen at least a couple of times larger than the entire device to allow breathing, before adding any other components - such as, you know, the pressurised, insulated container to allow the liquid oxygen to be stored in the first place, and the 'micro compressor' and gills that they are STILL maintaining that the device contains AND uses. So the brand new campaign is up to US$115,000 already after just a few hours... I could go on and on, including that this device would be much more dangerous to the untrained than even normal SCUBA gear due to the delivery of pure oxygen (see above for the risks of central nervous system toxicity) even though they are still claiming it doesn't require any training, the challenges of warming that liquid oxygen to a point where it wouldn't instantly cryogenically freeze your lungs as soon as you breathe in, the sheer impracticality of the canisters (there is no way you are getting one of those on a plane. They haven't clarified how much the canisters might cost - which might be why they had to refund and restart the campaign?) etc etc but I'm not sure it would make any difference. Update 4-17-2016: A demonstration of how the videos might have been faked. The first part uses a hidden hose and air tank, and the second part is a demonstration of an idea for making a more convincing video using a very small air tank hidden in the far side of the waistband of the diver's shorts, with a hose running underneath his top.