Wang et al., American Chemical Society (2017)
Wang et al., American Chemical Society (2017)

High-Tech Paper Could Be Reused Up to 80 Times

Wang et al., American Chemical Society (2017)
Wang et al., American Chemical Society (2017)

Even in an increasingly digital world, there's still a need for printed text. But wasting paper could be a thing of the past with new technology under development by a research team from the Lawrence Berkeley National Laboratory; the University of California, Riverside; and China's Shandong University. This new paper is printed with light instead of ink, allowing it to be reused up to dozens of times, Co.Design reports.

The paper, described in Nano Letters, is blue rather than white, and it's covered in a nanoparticle coating that is sensitive to UV light. These titanium dioxide nanoparticles are mixed with Prussian blue pigment (the blue color in blueprints), which becomes colorless when its particles gain electrons. The reaction that occurs when these pigments are exposed to UV light turns the blue clear. After about five days—or 10 minutes at 250°F—the paper fades back to solid blue, erasing the writing.

Image A shows the paper before anything has been printed on it. Images D-F show text 10 minutes, one day, and two days after it has been printed, respectively. Image Credit: Wang et al., American Chemical Society (2017)

A UV light printer can either print white text on a blue background or be programmed to print the background itself instead, resulting in blue text against a white background. The nanoparticle coating can be used over and over again, allowing one sheet of paper to be reprinted 80 times before it has to be thrown away.

The researchers hope to one day be able to print in full color with a similar system. They are currently working on a laser printer compatible with their light-printable paper. Until it hits the market, you’ll have to content yourself with buying notebooks that can be erased in the microwave.

[h/t Co.Design]

An Eco-Friendly Startup Is Converting Banana Peels Into Fabric for Clothes

A new startup has found a unique way to tackle pollution while simultaneously supporting sustainable fashion. Circular Systems, a “clean-tech new materials company,” is transforming banana byproducts, pineapple leaves, sugarcane bark, and flax and hemp stalk into natural fabrics, according to Fast Company.

These five crops alone meet more than twice the global demand for fibers, and the conversion process provides farmers with an additional revenue stream, according to the company’s website. Fashion brands like H&M and Levi’s are already in talks with Circular Systems to incorporate some of these sustainable fibers into their clothes.

Additionally, Circular Systems recycles used clothing to make new fibers, and another technology called Orbital spins those textile scraps and crop byproducts together to create a durable type of yarn.

People eat about 100 billion bananas per year globally, resulting in 270 million tons of discarded peels. (Americans alone consume 3.2 billion pounds of bananas annually.) Although peels are biodegradable, they emit methane—a greenhouse gas—during decomposition. Crop burning, on the other hand, is even worse because it causes significant air pollution.

As Fast Company points out, using leaves and bark to create clothing may seem pretty groundbreaking, but 97 percent of the fibers used in clothes in 1960 were natural. Today, that figure is only 35 percent.

However, Circular Systems has joined a growing number of fashion brands and textile companies that are seeking out sustainable alternatives. Gucci has started incorporating a biodegradable material into some of its sunglasses, Bolt Threads invented a material made from mushroom filaments, and pineapple “leather” has been around for a couple of years now.

[h/t Fast Company]

Undersea Internet Cables Could Be Key to the Future of Earthquake Detection

Considering that 70 percent of the planet is covered by oceans, we don't have all that many underwater earthquake sensors. Though there's plenty of seismic activity that happens out in the middle of the ocean, most detection equipment is located on land, with the exception of a few offshore sensor projects in Japan, the U.S., and Canada.

To get better earthquake data for tremors and quakes that happen far from existing sensors, a group of scientists in the UK, Italy, and Malta suggest turning to the internet. As Science News reports, the fiber-optic cables already laid down to carry communication between continents could be repurposed as seismic sensors with the help of lasers.

The new study, detailed in a recent issue of Science, proposes beaming a laser into one end of the optical fiber, then measuring how that light changes. When the cable is disturbed by seismic shaking, the light will change.

This method, which the researchers tested during earthquakes in Italy, New Zealand, Japan, and Mexico, would allow scientists to use data from multiple undersea cables to both detect and measure earthquake activity, including pinpointing the epicenter and estimating the magnitude. They were able to sense quakes in New Zealand and Japan from a land-based fiber-optic cable in England, and measure an earthquake in the Malta Sea from an undersea cable running between Malta and Sicily that was located more than 50 miles away from the epicenter.

A map of the world's undersea cable connections with a diagram of how lasers can measure their movement
Marra et al., Science (2018)

Seismic sensors installed on the sea floor are expensive, but they can save lives: During the deadly Japanese earthquake in 2011, the country's extensive early-warning system, including underwater sensors, was able to alert people in Tokyo of the quake 90 seconds before the shaking started.

Using existing cable links that run across the ocean floor would allow scientists to collect data on earthquakes that start in the middle of the ocean that are too weak to register on land-based seismic sensors. The fact that hundreds of thousands of miles of these cables already crisscross the globe makes this method far, far cheaper to implement than installing brand-new seismic sensors at the bottom of the ocean, giving scientists potential access to data on earthquake activity throughout the world, rather than only from the select places that already have offshore sensors installed.

The researchers haven't yet studied how the laser method works on the long fiber-optic cables that run between continents, so it's not ready for the big leagues yet. But eventually, it could help bolster tsunami detection, monitor earthquakes in remote areas like the Arctic, and more.

[h/t Science News]


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