What if your smartphone or laptop starts charging as soon as you walk in the door? Scientists have developed a specially-built room that can conduct energy to a variety of electronic devices within it without plugs or batteries.

It’s a custom test room of about 18 cubic meters, built from conductive aluminum(铝) panels with a metal pole running down the middle. When the scientists ran an electric current through the walls and pole following a set pattern, it generated two separate magnetic (磁的) fields: one that fills the center of the room and the other that covers the corners, thus allowing any devices within the space to charge.

By carrying out tests, scientists found their method could deliver 50 watts of power throughout the room. firing up all devices they tested. Without safeguards, running currents through the room's metal walls would typically fill it with two types of waves: electric and magnetic. This presents a problem, because electric fields can produce heat in biological tissues and pose a danger to humans. So the team built capacitors, devices that store electric energy, in the walls. “It limits the safe magnetic fields to the room volume while limiting risky parts to all the components built in the walls.” lead author Takuya Sasatani explains.

The scientists also tested the room’s safety, and the result showed the absorption of energy would remain well below acceptable limits. “We’re not saying this technology is safe under all circumstances—we’re still exploring,” says study co-author Alanson Sample. “But it shows us that there's still much area to explore.”

But applying the technology is still far in the future. It’s just too burdensome to put aluminum sheets all over the walls-that benefit doesn't make sense yet. “We’ve just developed a brand-new technique. Now we have to figure out how to make it practical,” Sample says. Meanwhile, scientists hope to improve the efficiency of power conduction and remove spots that the charge does not reach.

Don’t you just hate it when you have to answer an important phone call and you’re surrounded by potential eavesdropper (偷听者) ? You either have to whisper or go outside to keep the conversation private. Now, a new device (设备) aims to solve this problem by blocking your voice.

Hushme is a high - tech mask (口罩) that blocks the sound of the wearer’s voice. It connects to your phone by Bluetooth. It also comes with a pair of earphones. When you get a private call, all you have to do is put the mask on and it will do a good job of blocking your voice. But to ensure nothing gets through, Hushme also features external speakers that play a variety of sounds when you speak.

The Hushme mask comes in a variety of colors. It can be worn around the neck, like a regular pair of earphones. It attaches in front of your mouth thanks to a couple of very powerful magnets (磁铁). The sound options for covering your voice currently include the wind, ocean, rain, bird, monkey, squirrel, R2D2, laughing Minion and Darth Vader breath, but new ones could be added in the future. While Hushme is promoted as a phone call privacy protection device, you could always use it to protect your ears from loud mouth co - workers at the office. Just put this baby over their mouths and you can go on with your work.

Advertised as the “world’s first voice mask for mobile phones”, Hushme was shown at Centre for Environmental Studies (CES) at the beginning of this year. It’s not commercially available yet, but its makers plan to start a crowdfunding campaign, and to start selling it by the end of the year. Engadget reports that it will cost around $ 200.

The Food and Drug Administration (FDA) has to recall (召回) hundreds of foods every year. Like cookie snack packs with pieces of blue plastic hiding inside, dressing and sauce containing salmonella (沙门氏菌) or various jams containing with lead (铅).

It can take a few months before a recall is issued. But now researchers have come up with a method that might fast-track that process, leading to early detection and, ultimately, faster recalls. The AI system relies on the fact that people increasingly buy foods and spices (调味料) online. And people tend to write review s of products they buy online, which are like bread crumbs (面包屑) to food-safety officials sniffing (嗅) out dangerous products.

The researchers linked FDA food recalls from 2012 to 2014 to Amazon reviews of those same products. They then trained machine-learning algorithms (算法) to distinguish between reviews for recalled items and reviews for items that had not been flagged. And the trained algorithms were able to predict FDA recalls three quarters of the time. They also identified another 20,000 reviews for possibly unsafe foods, most of which had never been recalled. The results are published in Journal of the American Medical Informatics Association.

The World Health Organization estimates that 600 million people worldwide get sick annually from polluted food, and more than 400,000 people die from it. “So having tools that enable us to detect this a lot faster and hopefully investigate and do recalls faster will be useful not just in the U. S. but in other countries around the world as well.” Study author Elaine Nsoesie of Boston University. She did add one warning: even recalled products can still get five-star reviews. So stars alone don’t tell the whole sickening story. The proof, unfortunately, may still be in the pudding.