Scientists Create Origami That Can Fold Itself Using Light

Rob Felt, Georgia Tech
Rob Felt, Georgia Tech

Scientists at Georgia Tech have figured out how to create origami from light, no hands required. All the technique uses is a PowerPoint slide, a projector, and some resin. Georgia Tech mechanical engineer Jerry Qi and his colleagues exposed photo-absorbent resin to light patterns to get the material to bend into specific shapes, as they write in a paper in Science Advances.

The researchers put the designs they wanted to fold into a PowerPoint slide and projected that in grayscale onto resin in a Petri dish using a commercial projector, producing resin that folded itself into flowers, cranes, and a Miura fold.

Rob Felt, Georgia Tech

The bending of the liquid resin is affected by both the time it’s exposed to light and the intensity of that light. Qi explains to ResearchGate that when the layer of liquid resin is exposed to the light, it shrinks the layers of resin at different rates. The layer hit directly by the light cures faster than the layers farther down. Because the different sides of the resin aren’t curing at the same rate, it creates what he calls “nonuniform shrinkage stress,” bending the resin along that path of light as it solidifies.

Since the layers of resin are so thin, it's very difficult to make larger objects using this technique. The resin origami figures they've made so far are smaller than the face of a quarter.

Rob Felt, Georgia Tech

The Georgia Tech team suggests that this technique could be used to make soft origami machines, among other applications. They aren’t the only ones working on this technology, though. Recently, scientists at North Carolina State University created similar self-folding polymers that were controlled by different colored lights. Those researchers hoped to be able to remotely manipulate materials on satellites in space or for medical uses.

[h/t ResearchGate]

Amazon's Under-the-Radar Coupon Page Features Deals on Home Goods, Electronics, and Groceries

Stock Catalog, Flickr // CC BY 2.0
Stock Catalog, Flickr // CC BY 2.0

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Now that Prime Day is over, and with Black Friday and Cyber Monday still a few weeks away, online deals may seem harder to come by. And while it can be a hassle to scour the internet for promo codes, buy-one-get-one deals, and flash sales, Amazon actually has an extensive coupon page you might not know about that features deals to look through every day.

As pointed out by People, the coupon page breaks deals down by categories, like electronics, home & kitchen, and groceries (the coupons even work with SNAP benefits). Since most of the deals revolve around the essentials, it's easy to stock up on items like Cottonelle toilet paper, Tide Pods, Cascade dishwasher detergent, and a 50 pack of surgical masks whenever you're running low.

But the low prices don't just stop at necessities. If you’re looking for the best deal on headphones, all you have to do is go to the electronics coupon page and it will bring up a deal on these COWIN E7 PRO noise-canceling headphones, which are now $80, thanks to a $10 coupon you could have missed.

Alternatively, if you are looking for deals on specific brands, you can search for their coupons from the page. So if you've had your eye on the Homall S-Racer gaming chair, you’ll find there's currently a coupon that saves you 5 percent, thanks to a simple search.

To discover all the deals you have been missing out on, head over to the Amazon Coupons page.

Sign Up Today: Get exclusive deals, product news, reviews, and more with the Mental Floss Smart Shopping newsletter!

How Do Astronauts Vote From Space?

Astronaut Kate Rubins casts her ballot from space.
Astronaut Kate Rubins casts her ballot from space.

Earlier this week, NASA announced that astronaut Kate Rubins had officially cast her vote from a makeshift voting booth aboard the International Space Station. As much as we’d like to believe her ballot came back to Earth in a tiny rocket, the actual transmission was much more mundane. Basically, it got sent to her county clerk as a PDF.

As NASA explains, voting from space begins the same way as voting abroad. Astronauts, like military members and other American citizens living overseas, must first submit a Federal Postcard Application (FPCA) to request an absentee ballot. Once approved, they can blast off knowing that their ballot will soon follow.

After the astronaut’s county clerk completes a practice round with folks at the Johnson Space Center in Houston, they can start the real voting process. The astronaut will then receive two electronic documents: a password-protected ballot sent by the Space Center’s mission control center, and an email with the password sent by the county clerk. The astronaut then “downlinks” (sends via satellite signal) their filled-out ballot back to the Space Center attendants, who forward it to the county clerk. Since the clerk needs a password to open the ballot, they’re the only other person who sees the astronaut’s responses. Then, as NPR reports, they copy the votes onto a regular paper ballot and submit it with the rest of them.

Though Americans have been visiting space for more than half a century, the early jaunts weren’t long enough to necessitate setting up a voting system from orbit. That changed in 1996, when John Blaha missed out on voting in the general election because his spaceflight to Russia’s space station Mir began in September—before absentee voters received their ballots—and he didn’t return until January 1997. So, as The Washington Post reports, NASA officials collaborated with Texas government officials to pass a law allowing astronauts to cast their ballots from space. In the fall of 1997, David Wolf became the first astronaut to submit his vote from a space station. The law is specific to Texas because most active astronauts reside there, but NASA has said that the process can be done from other states if need be.