Imagine if you could fly around on a jet scooter, print out your lunch or sleep on a floating cloud? From flying vehicles to 3D printers, and more, we take a look at 30 wonder products which, due to technological or other constraints, have never seen the light of day.

Conceptualised by San Francisco-based designer Norio Fujikawa in 2009, JetScooter is a fuel-efficient flying scooter rocking retro styling, a kind of Vespa with wings. Though this particular flying vehicle never got off the ground, similar flying vehicle inventions are set to be commonplace in the not too distant future.

A refreshing deviation from conventional computer design, this UFO-esque latop/desktop hybrid was imagined by Korean creative Won-Seok Lee in 2008, but remains a mere concept. It boasts an omni-directional projector in place of a monitor, as well as a membrane keyboard that disappears when not in use.

Like literally floating on a cloud, relaxing on this bliss-inducing sofa from 2009 by China's D.K. & Wei Design would be heavenly. A super-strong magnet in the base makes the sofa, which consists of extra-lightweight plexiglass and fluffy upholstery, levitate as if by magic. The tech for this bed is theoretically possible although, to our dismay, it hasn't been made as yet.

Samsung and Huawei are poised to launch foldable phones next year, but the idea has been around for ages. In 2009 for instance Japanese tech firm Kyocera came up with this wallet-like concept model, which features a foldable OLED screen and bendy keyboard.

A finalist in the 2010 Electrolux Design Lab competition, this ridiculously futuristic fridge by Russian designer Yuriy Dmitriev is filled with a special green gel that suspends and cools food in individual pods using very little energy.

Can't decide between the shower or the bath? The 90° vertical bathtub combines the best of both worlds. Users can stand or float in the rather unpractical but fabulous tub, which was conceptualised in 2011 by Taiwanese designer Ethan Lai for the Roca Design Competition.

Staying in the bathroom, towels can harbour all sorts of nasty germs and don't tend to be washed as often as they should. Cue the Dry Clean, which was devised by China's puredesign in 2011. The concept heated rail has a mini turbine to fan towels dry and uses UV light to disinfect them. Clever. If only it was a reality...

Dreamed up by industrial designer Hong Ying Guo in 2012, the Purifi Pan sucks up cooking smells and smoke, leaving the rest of the kitchen odour and smoke-free, and negating the need for an extractor fan. Shame it never made it past the drawing board.

An eco-friendly home of the future, this circular house, which floats on the sea, is powered entirely by tidal and solar energy. British architect Margot Krasojević created the concept in 2014, but it looks like being some time yet before the technologies the house deploys will be viable.

An Electrolux Design Lab 2012 finalist, Memory by Chinese designer WenYao Cai is a coffee machine that uses hand print recognition to rustle up the right cup of coffee for the right person based on their personal preference, which is set beforehand.

Flying cars are of course set to become a reality in the relatively near future, but we doubt the first operational models will be as cool as the Audi Shark. A cross between a motorcycle and a plane, the design concept by Turkish creative Kazim Doku won the 2009 World Auto Design Contest.

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Viennese designer Benjamin Cselley thought up this office-chair-meets-exercise-machine in 2011, but it never even made it to the prototype stage. The Fitness@Work chair has everything from a rodeo seat to resistant handles, and can be used to firm the abdominal muscle, strengthen the back, improve overall tone, and more.

If you can't stand the chore of washing, drying and ironing clothes, Clean Closet by Swedish creative Michael Edenius would be a godsend. An in-built scanner analyses clothes for odour and stains, cleaning them when need be, and making sure they stay crease-free. If only the technology for this 2010 concept were available.

Just the thing for students who want to sell their textbooks at the end of a semester, Fader, which was proposed by New York product development firm Quirky in 2012 but never produced, is a highlighter pen filled with ink that disappears after six months.

This clever wearable concept phone from 2009 integrates a thermometer and other health sensors to monitor the user's vital signs. While designer Lu Yin's creation never made it past the drawing board, today's smartwatches contain much of the envisaged technology.

Toasting bread on the go is a piece of cake with this nifty little concept gadget by Been Kim from 2009. The blade of the ceramic knife heats up to blistering temperatures, hot enough to toast a piece of bread by simply gliding it across the surface. Whether it would work in practice however is anyone's guess.

The mega-flexible Napkin PC won its American creator Avery Holleman first prize in the 2009 Next-Gen PC Design Competition. The gizmo, which never got past the concept stage, features a base station filled with e-paper 'napkins' and stylus pens.

MIT grad students Marcelo Coelho and Amit Zoran concocted this clever 3D food printer in 2010, but it is yet to be made due to technological constraints. The personal food factory features canisters that store ingredients that are blended by the machine and 'printed' in hot or cold layers, depending on the selected recipe.

Part clothes line, part tumble dryer, this concept gizmo from 2012 by London-based designer Jack McCulloch dries soaking-wet clothing in minutes using advanced infrared, dehumidifying and fan technologies. Just how effective and energy efficient this gizmo would be in reality though is open to debate.

This round flying car was one of three concepts that made the final of the People's Car Project, a competition that Volkswagen launched in China in 2011. Unfortunately, this particular vehicle would require electromagnetic roads to work.

A finalist in the 2014 Electrolux Design Lab competition, this detergent-free washing machine concept by Korean designer Chan Yeop Jeong contains robot fish embedded with tiny sensors to detect dirt. The offending particles are then 'eaten' by the mechanical fish, which can be used again and again.

Another Electrolux Design Lab competition entry, this concept by California-based industrial designer Akifusa Nakazawa also uses robot fish, but instead of washing clothes, the swimming bots clean dishes, glassware and cutlery, with the added bonus of turning the leftover food into biofuel.

French creative Josselin Zaïgouche came up with this incredible phone concept back in 2010 incorporating technologies that are likely to be available in the near-ish future. His mouse-like Apple Black Hole wows with a touchless holographic interface and can even levitate.

Commuting on packed buses or trains would be a whole lot more fun if Chinese designer Jian Qian's Strap Game had gone beyond the conceptual stage. The strap contains a gaming system that turns on when a passenger grabs the handle.

Conceptualised in 2008, this digital artist's palette by Canadian artist and designer Yana Klimava allows the user to create computer art as they would a traditional painting. Budding PC painters can mix and thin pigments, use a range of stylus brushes and more. Why no big PC maker has picked up this genius idea is anyone's guess.

Another jaw-dropping tub concept, Bathingsphere by the Alexander Zhukovsky Design Studio in Russia is a glass ball tub suspended from the ceiling. Conceived in 2013, the ball, which would no doubt require some seriously creative plumbing if it ever made it into production, is temperature-controlled and features a rainfall shower effect and calming mood lighting.

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Thought up in 2009, this counter-top concept gizmo by designer Yitu Wang uses a domed shield made up of fine water vapour suspended in the air to keep oxygen, dust and dirt out to stop fruit and vegetables from going bad, prolonging shelf life significantly. Getting the technology on point, however, would be a tough challenge.

This entry from the 2010 Electrolux Design Lab competition was submitted by Londoner Joshua Harris. His 3D clothing printer, which connects to retailers, does exactly what it says on the tin, allowing users to instantly print out clothing they've snapped up online. Hopefully it's a sign of things to come.

Not into bulky smartphones? This concept from 2014 by industrial designer Issam Trabelsi was created with people like you in mind. The tiny device, which is technically feasible but may be a tad impractical, wraps around the index finger and, like a smartwatch, would be used to make and receive calls, and issue notifications. Watch this space.

The ultimate doghouse, this luxe pooch pad comes complete with a treadmill, automatic feeder and hydrotherapy bath. The two-room kennel did actually make it past the drawing board, but Samsung only manufactured a single model, which was given away as first prize in a 2015 Twitter competition. You never know what the future holds, though.

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