Ink-free printer
The Prepeat ink-free printer, as spotted by Coventry University, was demonstrated in 2010. It offers reusable plastic sheets that apply to the paper using heat. No ink, no toner, no nothing. The user can reprint a document 1,000 times. Unfortunately, with a four-figure price tag and no sign of mass market availability, it seems the Prepeat could never quite generate enough heat.
Color e-ink
Black and white e-ink screens have found a successful niche as a way to read books without straining the user's eyes. Amazon CEO Jeff Bezos declared in 2009 that a Kindle with a color e-ink screen was "multiple years away." Over a decade later, the color e-ink screen remains obscure.
E-ink, the company that develops the technology, announced in January 2020 a new generation screen that could display over 40,000 colors. Color e-ink tablets are gradually starting to reach the market, but whether they'll break into the mainstream remains to be seen.
The problem was twofold: the technology wasn't really as great as it seemed in the video, and wearers more interested in their gadget than social interactions were dubbed "glassholes."
Rumors suggest Apple is planning to try its own hand at a headset – with one questionable report even suggesting they could arrive in a Steve Jobs edition. It seems the dream may not be over just yet.
Fusion energy
Unlike nuclear fission that splits atoms apart, nuclear fusion is about smashing them together to ultimately generate electricity. It could mean minimal waste, zero-emissions energy at a time when carbon emissions are wrecking the planet. The Guardian billed it in 2014 as a technology that "has been ‘30 years away’ for several decades."
Work is still underway to make it a reality. Oxford-based First Light Fusion has the world's largest fusion machine of its kind in its labs, while a $23.5 billion ITER facility has started a five-year construction period.
Hands-free gaming
When Microsoft first demonstrated the Kinect in 2009 under its codename "Natal," it featured a flashy demonstration from famed video game designer Peter Molyneux – a figure who has a reputation for outlandish promises. Perhaps little surprise then that "Project Milo," a fully hands-free game where players could chat and interact with a video game character with no controller, never quite came to fruition.
After bundling the Kinect with the Xbox One in 2013 to make the camera a mainstay of video game interaction, it ultimately dropped the bundle the following year and the sensor gradually faded away.