Posts Tagged ‘invention’


No ink required to print on this paper — yet look how readable the type is. (Photo: University of California, Riverside/YouTube)

by BRYAN NELSON

As much as 40 percent of our landfills consist of paper and cardboard, and a major source of that material comes from office supplies. Just think of all the paper that gets used and discarded on a daily basis through the printer in your office alone. Even if that paper gets recycled, it still presents a different sort of problem due to pollution associated with the ink removal process.

Then there’s the concern about deforestation. In the United States, about one-third of all harvested trees are used for paper and cardboard production.

Paper and printing is a problem, to be sure. But now, thanks to a breakthrough from a team of scientists at Shandong University in China, the University of California, Riverside, and Lawrence Berkeley National Laboratory, it might be a problem with a solution.

The researchers have invented a new type of rewritable paper that can be printed with light — no ink required. The paper feels like normal paper to the touch, but it’s coated in color-changing nanoparticles that react to UV light. The technology works simply enough: a UV light printer zaps the paper everywhere except where the text is meant to be. The text then boldly stands out against the clear, light-zapped background.

“The greatest significance of our work is the development of a new class of solid-state photoreversible color-switching system to produce an ink-free light-printable rewritable paper that has the same feel and appearance as conventional paper, but can be printed and erased repeatedly without the need for additional ink,” explained Yadong Yin, chemistry professor at the University of California, Riverside. “Our work is believed to have enormous economic and environmental merits to modern society.”

The researchers published a paper on their work in the journal Nano Letters.

The nanoparticles return to their original background state if left untreated for five days, so the text will disappear naturally. (It certainly beats a paper shredder.) But if you wanted to erase and rewrite onto the same paper sooner than that, it will also revert back if heated for only about 10 minutes at 250 degrees Fahrenheit. It’s kind of like a hardcopy version of Snapchat, assuming you’ve got the proper equipment on hand to erase a message after it’s been read.

“We believe the rewritable paper has many practical applications involving temporary information recording and reading, such as newspapers, magazines, posters, notepads, writing easels, product life indicators, oxygen sensors, and rewritable labels for various applications,” said Yin.

Aside from producing little waste, the technology is also inexpensive. The coating materials are so cheap that they add almost nothing to the cost of a sheet of paper. Meanwhile, the printing technology ought to be cheaper than traditional inkjet printers simply because no ink is required. (Imagine never having to change out your ink cartridge again!)

And of course, because the paper can be re-used more than 80 times before the effect is dulled, the technology saves on the cost of paper as well.

“Our immediate next step is to construct a laser printer to work with this rewritable paper to enable fast printing,” said Yin. “We will also look into effective methods for realizing full-color printing.”

http://www.mnn.com/green-tech/research-innovations/stories/scientists-invent-paper-can-be-printed-light-instead-ink

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paperfuge_hands

Centrifuges, which separate materials in fluids by spinning them at great speed, are found in medical labs worldwide. But a good one could run you a couple grand and, of course, requires electricity — neither of which are things you’re likely to find in a rural clinic in an impoverished country. Stanford researchers have created an alternative that costs just a few cents and runs without a charge, based on a children’s toy with surprising qualities.

It’s a whirligig, and it’s a simple construction: a small disc, probably a button, through which you thread a piece of string twice. By pulling on the threads carefully, you can make the button spin quite quickly. You may very well have made one as a child — as Saad Bhamla, one of the creators of what they call the Paperfuge, did.

“This is a toy that I used to play with as a kid,” he says in a video produced by the university. “The puzzle was that I didn’t know how fast it would spin. So I got intrigued and I set this up on a high-speed camera — and I couldn’t believe my eyes.”

The whirligig was spinning at around 10,000 to 15,000 RPMs, right in centrifuge territory. The team then spent some time intensely studying the motion of the whirligig, which turns out to be a fascinatingly efficient way to turn linear motion into rotational motion.

The team then put together a custom whirligig with a disc of paper into which can be slotted a vial with blood or other fluids. By pulling on the strings (they added handles for ease of use) for a minute or two, less than a dollar’s worth of materials does a superb job of replicating the work of a device that costs thousands of times more. They’ve achieved RPMs of 125,000 and 30,000 G-forces.

“There is a value in this whimsical nature of searching for solutions, because it really forces us outside our own sets of constraints about what a product should actually look like,” said Manu Prakash.
They’ve just returned from field tests in Madagascar, where they tested the device and checked in with local caregivers. Up next will be more formal clinical trials of the Paperfuge’s already demonstrated ability to separate malaria parasites from blood for analysis.

If the concept of a simple, cheap alternative to existing lab equipment rings a bell, you might be remembering Foldscope, another project from Prakash. It put a powerful microscope in flatpack form for a few bucks, enabling scientific or medical examination at very low budgets.

The details of the Paperfuge and its development by Bhamla, Prakash and the rest of the team can be found in the most recent issue of Nature Biomedical Engineering: http://www.nature.com/articles/s41551-016-0009

This 20-cent whirligig toy can replace a $1,000 medical centrifuge

Thanks to Kebmodee for bringing this to the It’s Interesting community.

Two engineering students at George Mason University have created a potentially revolutionary fire extinguisher that uses sound to fight blazes.

The brainchild of engineering seniors Viet Tran and Seth Robertson, the device uses low frequency sound waves to extinguish fires.

According to its makers, the device could be used in a number of settings, from a kitchen stovetop to tackling large infernos. For example, the extinguisher could be attached to a drone for fighting forest and building fires, keeping firefighters out of harm’s way.

Tran and Robertson hold a preliminary patent application for their invention.

http://www.foxnews.com/tech/2015/03/27/bass-battles-blaze-george-mason-students-invent-sound-based-fire-extinguisher/