4-D Printing Means Building Things That Build Themselves

H. Jerry Qi, associate professor of mechanical engineering at Colorado University, holds simple models printed using polymers that have "shape memory." The flat piece on the left can reshape itself into a box with the application of heat.

Glenn J. Asakawa/University of Colorado H. Jerry Qi, associate professor of mechanical engineering at Colorado University, holds simple models printed using polymers that have "shape memory." The flat piece on the left can reshape itself into a box with the application of heat.

Glenn J. Asakawa/University of Colorado

In our Weekly Innovation series, we pick an interesting idea, design or product that you may not have heard of yet. Got an innovation you think we should feature? Fill out our form.

The advent of 3-D printing brought on a number of innovations worthy of news coverage. Printers have created prosthetic hands, action figures, food, even blood vessels, simply by depositing layer after layer of different kinds of ink.

Now a handful of engineers around the world are trying to push the boundaries one step further — by printing objects that can build themselves.

It's called 4-D printing, and the fourth dimension in this case is time. Here's how it works: A 3-D printer with extremely high resolution uses materials that can respond to outside stimuli, like heat or light, as ink. The resulting structure can change, move or even assemble itself after it's been printed.

One team of researchers led by H. Jerry Qi, an associate professor at the University of Colorado Boulder, is using heat and mechanical pressure to transform flat objects into three-dimensional structures. They printed an unfolded box with glassy polymer fibers — a composite material that has "shape memory behavior" — along the folds. They heated it, pulled on the sides and cooled it, and the flat structure responded by folding into a box.

Another team — a collaboration between University of Pittsburgh, University of Illinois at Urbana-Champaign and Harvard University — recently garnered an $855,000 grant from the U.S. Army Research Office to explore how adaptive materials can respond to stimuli like light or temperature.

It's not unlike how the body works, says Professor Anna Balazs at Pittsburgh. It responds continuously, in complex ways, to the world around it.

"The idea is the use the full arsenal of 3-D printing," she says. "It allows complicated objects to morph their structure. You're not just going to print one object, one use."

One potential application? You could make a fabric that changes color in response to light or changes permeability in response to temperature. It could provide a protective layer in the presence of toxic chemicals — that would be particularly useful for soldiers in combat.

Another application, Qi says, is useful in places where traditional manufacturing is impractical — like in space. You could make an instrument that's small and flat and expand it aboard a spacecraft.

You can't make these products at home, at least not yet. The printers are still being tested by individual academic labs, along with the responsive inks. Balazs says integrating the two for reliable commercial use will probably take another three to five years.

Until then, some researchers will be trying, as always, to take technology to the next level.

Skylar Tibbits, who researches self-assembly at MIT, is looking at how construction processes might be simplified by using materials that respond to shaking — or even to sound. His vision is lofty, but he has arguably the most imaginative ideas of 4-D printing research so far.

"Manufacturing could be more like growing," he said in a BBC interview in July. "Maybe the construction sites in the future, we play Beethoven and structures build themselves."

View the original article here

Another Election?! Relax, This One's To Name A Baby Panda

You can help select a name for the National Zoo's new panda cub.

Abby Wood/Smithsonian's National Zoo You can help select a name for the National Zoo's new panda cub.

Abby Wood/Smithsonian's National Zoo

Fresh off Tuesday's election, another is just around the corner: The National Zoo wants you to help name its new panda cub by casting a vote at Smithsonian.com.

You can vote online (no photo identification required and the balloting continues until Nov. 22).

At NPR, we always strive to ensure that our audience is informed of the candidates — even when they're names for pandas.

The Smithsonian's National Zoo in Washington, D.C., has put forth five possible names for the female cub born this summer — all Chinese names, of course — so we talked to NPR's Beijing correspondent, Anthony Kuhn, for some help in understanding them:

— Bao Bao (??) (bow-BOW) — Precious, treasure. "Bao means treasure and when you say 'Bao Bao,' it usually means baby, as in 'Bao Bao's diapers need changing [or] Bao Bao is hungry,' " Anthony says.

— Ling Hua (??) (ling-HWA) — Darling, delicate flower. "Ling is actually the sound you make when you plink a piece of jade," says Anthony. It also happens to be the name of a wildly popular Chinese pop singer.

— Long Yun (??) (long-YOON) — Long is the Chinese symbol for dragon and "yun" is a pleasing sound, something that rhymes. It translates roughly as "the sound of the dragon," Anthony says, which is meant to be "auspicious, not scary."

— Mulan (??) (moo-LAHN) — Legendary young woman, a smart and brave Chinese warrior from the fifth century — "the legendary woman warrior who dressed as a man to join the army," Anthony says. Also, the name for the magnolia flower in China and the United States.

— Zhen Bao (??) (jen-BAO) — Treasure, valuable. "Zhen Bao is close to Bao Bao," Anthony says. "Zhen also means something precious. So, they are both very close, but it doesn't have the same meaning as baby."

The official naming ceremony at the National Zoo will take place Dec. 1 — when the cub turns 100 days old.

And, if you need a panda fix before then, here's a behind-the-scenes video shot in 2008 by NPR's David Gilkey at the Chengdu Research Base of Giant Panda Breeding.

View the original article here

As Mirrors Beam Light To Town, Norwegians Share Patch Of Sun

Mirrors erected on a Norwegian mountainside reflect sunlight onto the town below, which is cut off from direct sunlight for about six months a year.

NTB Scanpix/Reuters/Landov Mirrors erected on a Norwegian mountainside reflect sunlight onto the town below, which is cut off from direct sunlight for about six months a year.

NTB Scanpix/Reuters/Landov

The small town of Rjukan has long had to make do without sunlight during the cold Norwegian winters.

But that changed Wednesday, when the town debuted a system of high-tech mirrors to reflect sunlight from neighboring peaks into the valley below.

Rjukan, originally founded 100 years ago as an industrial outpost for the energy company Norsk Hydro, is nestled between several mountains and does not receive direct sunlight from late September to mid-March — nearly six months out of the year.

"Of course, we notice it when the sun is shining," says Karin Ro, who works for the town's tourism office. "We see the sky is blue, and then we see that down in the valley it's darker — it's like on a cloudy day."

People gather in the central square of Rjukan, Norway, on Wednesday to bask in the sun reflected by mirrors on a nearby mountainside.

NTB Scanpix/Reuters/Landov People gather in the central square of Rjukan, Norway, on Wednesday to bask in the sun reflected by mirrors on a nearby mountainside.

NTB Scanpix/Reuters/Landov

Wednesday, residents of Rjukan received their first dose of winter sun down in the valley: A series of reflective panels on a nearby mountainside were put to use for the very first time.

The mirrors are controlled by a computer that directs them to shift along with the sun throughout the day (and to pivot closed during windy weather). They reflect a concentrated beam of light onto the town's central square, creating an elliptical patch of sunlight roughly 600 square meters. When the light appeared, Rjukan residents flocked together.

"People have been sitting there and standing there and taking pictures of each other," Ro tells NPR's Arun Rath. "The town square was totally full. We are not that big of a town, so I think almost all the people in the town were on the town square."

The 3,500 residents cannot all bask in the sun at the same time. Nevertheless, Ro says, the new light supplied by these mirrors feels like more than enough for the town's sun-starved residents.

"It's not very big," she says, "but it is enough when we are sharing."

View the original article here

Childhood Maltreatment Can Leave Scars In The Brain

Girls are particularly vulnerable to brain changes caused by stress or trauma, researchers say.

Allen Johnson/iStockphoto.com

Maltreatment during childhood can lead to long-term changes in brain circuits that process fear, researchers say. This could help explain why children who suffer abuse are much more likely than others to develop problems like anxiety and depression later on.

Brain scans of teenagers revealed weaker connections between the prefrontal cortex and the hippocampus in both boys and girls who had been maltreated as children, a team from the University of Wisconsin reports in the Proceedings of the National Academy of Sciences. Girls who had been maltreated also had relatively weak connections between the prefrontal cortex the amygdala.

Those weaker connections "actually mediated or led to the development of anxiety and depressive symptoms by late adolescence," says Ryan Herringa, a psychiatrist at the University of Wisconsin and one of the study's authors.

Maltreatment can be physical or emotional, and it ranges from mild to severe. So the researchers asked a group of 64 fairly typical 18-year-olds to answer a questionnaire designed to assess childhood trauma. The teens are part of a larger study that has been tracking children's social and emotional development in more than 500 families since 1994.

The participants were asked how strongly they agreed or disagreed with statements like, "When I was growing up I didn't have enough to eat," or "My parents were too drunk or high to take care of the family," or "Somebody in my family hit me so hard that it left me with bruises or marks."

There were also statements about emotional and sexual abuse. The responses indicated that some had been maltreated in childhood while others hadn't.

All of the participants had their brains scanned using a special type of MRI to measure the strength of connections among three areas of the brain involved in processing fear.

One area is the prefrontal cortex, which orchestrates our thoughts and actions, Herringa says. Another is the amygdala, which is "the brain's emotion and fear center," he says, and triggers the "fight or flight" response when we encounter something scary.

Herringa says messages from the amygdala to the prefrontal cortex are often balanced by input from a third area, the hippocampus, which helps decide whether something is truly dangerous. "So, for example, if you're at home watching a scary movie at night, the hippocampus can tell the prefrontal cortex that you're at home, this is just a movie, that's no reason to go into a full fight or flight response or freak out," Herringa says.

At least that's what usually happens when there's a strong connection between the hippocampus and prefrontal cortex, and the fear circuitry is working correctly.

But Herringa says brain scans showed that in adolescents who had been maltreated as children, the connection with the hippocampus was relatively weak. He says in girls who had been maltreated, the connection with the amygdala was weak, too.

That suggests the fear circuitry wasn't working the way it should, Herringa says. The result seems to explain something he sees in many young patients with anxiety and depression and a history of maltreatment. "These kids seem to be afraid everywhere," he says. "It's like they've lost the ability to put a contextual limit on when they're going to be afraid and when they're not."

The finding that girls have weaker connections to two areas of the brain, not just one, could help explain why they seem to be more sensitive than boys to maltreatment, Herringa says.

The results of the new study are important because they suggest better ways to diagnose and treat mental problems related to maltreatment, says Greg Siegle, a psychologist at the University of Pittsburgh.

"Maltreatment is a disorder where often people are not even aware of the extent of their symptoms," Siegle says. So having an objective test would be "a significant advance," he says.

The study also shows that brain researchers are making some progress in their quest to make mental health care more like physical health care, where objective tests confirm a diagnosis and measure the effectiveness of treatment, Siegle says.

"In psychiatry, in psychology, we very rarely have those tests because we just don't know the biological and brain mechanisms," he says. "This study is starting to get at what mechanisms we should be looking at."

View the original article here

Forget Barley And Hops: Craft Brewers Want A Taste Of Place

The brewers at Scratch Brewing Company add wild plants like spicebush, goldenseal, wild ginger, chanterelles and wild rose root to their beer to give it the flavor of the Illinois woods.

Aaron Kleidon/Scratch Brewing Company The brewers at Scratch Brewing Company add wild plants like spicebush, goldenseal, wild ginger, chanterelles and wild rose root to their beer to give it the flavor of the Illinois woods.

Aaron Kleidon/Scratch Brewing Company

Last week, Aaron Kleidon went for a walk in the Illinois woods and returned with a bag of lotus seeds. The seeds were bound not for his dinner plate, but for his pint glass.

In a few months, Kleidon will have lotus-flavored beer at the small brewpub Scratch Brewing Company, which he owns with two friends in Ava, Ill. The microbrewery specializes in beers with seeds, leaves, roots, fruits and fungi foraged from a nearby wooded property. The brewers have even made a saison from chanterelle mushrooms.

Why, you may ask, would anyone want to add strange seeds and mushrooms to their beer? The answer is to create a taste of place. It's a concept long recognized by chefs and winemakers, who call it terroir, but is mostly absent from the craft of brewing.

This approach challenges the placelessness of mainstream brewers, who mostly use the same ingredients grown in the same places — barley from the Great Plains and hops from the Pacific Northwest.

"Beer should have a connection with the landscape," says Portland-based beer lover Eric Steen. In 2011, Steen started a program called Beers Made by Walking that invites brewers to go hiking with an eye out for trail-side plants to use in their beers. Steen's beer walks have involved such major breweries as Deschutes and New Belgium, and have resulted in oddities like a sour chokecherry beer, a sage-juniper IPA and a blonde ale brewed with stinging nettles and salmonberries.

Across the country, in backwoods and backyards, there are others searching for ingredients to flavor their beer. This summer, brewers around Washington, D.C., held a tasting event called Foraged Cask, which showcased beers made with unusual additions like mint, mulberries and lavender. And for several years, Chris Haas, head brewer at Desert Edge Brewery in Salt Lake City, has trekked into the local mountains late each summer to collect wild-growing hops.

At Uncommon Brewers in Santa Cruz, Calif., owner Alec Stefansky brews a red ale using maple-scented candy cap mushrooms. Stefansky, who has also experimented with fragrant redwood branches, says using wild, local ingredients in his beer is a way "to make flavors that are uniquely Northern Californian."

For his candy cap beer — called Rubidus Red, after the candy cap's Latin name — Stefansky collects the mushrooms himself each fall and winter. He says that the maple syrup aroma of dried candy caps is so potent that a single cup will do for seven barrels of the beer. What's more, if a person drinks just 2 or 3 pints of Rubidus Red, he or she will begin to smell deliciously like the fungus, according to Stefansky.

"You'll wake up smelling like breakfast," he says.

Imprinting beer with the flavor and scent of the South is a focus at Fullsteam Brewery, in Durham, N.C., founder Sean Lilly Wilson tells The Salt. The brewery features both wild ingredients and those grown on local farms — like hickory-smoked barley, sweet potatoes, local corn grits, figs from neighborhood trees, pawpaw fruits and wild American persimmons.

Brewing with foraged edibles may seem like another eccentric step forward by the ever-innovating craft beer industry, but Steen at Beers Made by Walking says it is actually a step backward.

"Historically, there were all sorts of herbs with flavor and medicinal qualities used in beer," he explains. "So, this is nothing new or special. It's really quite an old tradition."

View the original article here

Galaxy Quest: Just How Many Earth-Like Planets Are Out There?

This is an artist's illustration of Kepler-62f, a planet in the "habitable zone" of a star that is slightly smaller and cooler than ours. Kepler-62f is roughly 40 percent larger than Earth.

NASA/JPL-Caltech/T. Pyle

A team of planet hunters estimates that about 22 percent of the sun-like stars in our galaxy may have planets about the size of Earth that are bathed in similar amounts of sunlight — and potentially habitable.

That's the conclusion of a new analysis of observations taken by NASA's Kepler Space Telescope, which was launched in 2009 to hunt for potentially habitable Earth-like planets around other stars.

Kepler's goal was to find out if planets like Earth were cosmic rarities or a common occurrence. The telescope continually monitored the brightness of more than 145,000 stars, watching for telltale dips in brightness that might indicate a planet was passing between the star and the telescope.

At a conference to discuss Kepler findings this week, scientists who have combed through the first three years of data say that so far, they've detected indications of 3,538 possible planets, of all different sizes.

Of those planets, 104 are in the so-called habitable zone, where temperatures are mild enough to potentially allow life. Of those, "we're finding about 24 planets that are actually less than twice the size of the Earth," says William Borucki, the principal investigator for the Kepler mission at NASA Ames Research Center. At that size, he says, you might very well expect at least some or many of them to be rocky rather than gaseous.

Earlier this year, however, a critical part of the telescope failed, cutting its work short. Scientists worry that they may not have had enough time to determine how often Earth-like planets orbit sun-like stars.

Now, Erik Petigura and Geoffrey Marcy of the University of California, Berkeley, along with Andrew Howard of the University of Hawaii, have tried to answer that question with an extrapolation that used Kepler data from 42,000 sun-like stars.

They report in the Proceedings of the National Academy of Sciences that they found 603 likely planets, including 10 that are roughly Earth-sized and receive similar amounts of sunlight.

They also checked how well their software could detect Earth twins by creating data for fake planets and seeing how many of these fake planets were picked up or missed.

"You can hope that you are finding all the planets, or you can make guesses about how many planets you are missing, but you really don't know until you subject ... your analysis to a complex and thorough battery of tests," Petigura says.

Other planet hunters have been closely examining the group's work, says Natalie Batalha, Kepler mission scientist at NASA Ames Research Center.

"This is the first time that a team has offered such a number for stars like the sun, based on a thorough detection analysis," says Batalha. "My office was crowded with people, actively talking about the details of the work. The mood was very festive, and the dialogue was very productive."

David Charbonneau of Harvard University says the researchers have "done a careful study, and the results are very interesting."

But he notes that the team did not detect a single planet that is the same size and temperature as Earth. Instead, he points out, the group found planets that are larger and hotter, and used them to calculate the prevalence of more Earth-like worlds.

"The analysis of the Kepler data is by no means finished, and with dedicated effort it may be possible to further clean out the noise and some true Earths may pop out — but for now we have to be satisfied with knowing the population of planets that are broadly Earth-like, but in truth are probably too big and too hot for life," Charbonneau told NPR via email.

Earlier this year, Charbonneau and his colleague Courtney Dressing unveiled a study showing that around 15 percent of small red dwarf stars have a roughly Earth-sized planet in their habitable zones.

Marcy says if you combine that result with this newer study looking at sun-like stars, it suggests that our Milky Way galaxy contains something like 40 billion Earth-sized planets with lukewarm temperatures. "So that's really the stunning number, I think," says Marcy.

View the original article here

How Pictures Of Infant Boy's Eyes Helped Diagnose Cancer

A milky eye can be a sign of early cancer of the retina.

Courtesy of Bryan Shaw A milky eye can be a sign of early cancer of the retina.

Courtesy of Bryan Shaw

Bryan Shaw never expected to write a research paper about a rare eye cancer.

He's a chemist who works on how metals and proteins interact. But life has a funny way of interrupting the best-laid plans, and now Shaw may be on to a powerful new way to detect retinoblastoma in newborns. Such early detection could mean children with the disease would have a better chance of keeping their eyes and staying alive.

Shaw's scientific odyssey begins in May 2008, when he and his wife, Elizabeth, had a baby boy, Noah. Bryan was a postdoc at Harvard University at the time.

When Noah was 3 months old, Elizabeth noticed that sometimes when she took a flash picture of Noah with their digital camera, she would see a white reflection come back from his eyes instead of the usual red dot. She had read in a parenting magazine that this could be an early sign of retinoblastoma, so naturally as a first-time parent she assumed the worst. As husbands are wont to do, Bryan assured her she was crazy.

But on their next visit to the pediatrician, the doctor dutifully shined a penlight into Noah's eyes, since a white reflection from this simple eye exam can also detect the retinoblastoma tumor. The pediatrician didn't like what she saw, so she sent the Shaws to an ophthalmologist, who confirmed the worst: Noah had tumors in both eyes.

There followed months of chemotherapy, radiation, and ultimately surgery to remove Noah's right eye — and eventually years of checkups.

At first, Shaw says, he was too distraught to think about his son's cancer in scientific terms. But one day when Noah was 2, Bryan was in the waiting room while Noah was getting therapy, and he started thinking about the baby pictures that first revealed the tumor. He wondered if there was a way to track the disease back to the day the tumors first appeared.

He started small, but ultimately he would end up digitizing thousands of pictures he and Elizabeth had taken of Noah, searching for the first sign of leukocoria, as the white-eye condition is technically known.

"It first showed up in a picture taken when Noah was 12 days old," says Shaw. It didn't appear in all the pictures taken around that time. The tumor was small then, and the camera angle had to be just right to get the white reflection. But by 3 months there were days when nearly all the pictures showed signs of leukocoria.

Shaw is now on the faculty of Baylor University in Waco, Texas. He collaborated with the ophthalmologist who treated Noah at the Massachusetts Eye and Ear Infirmary and Noah's oncologists at Dana Farber Cancer Institute to produce a paper published in PLOS ONE.

In addition to pictures of Noah, the paper analyzes family photos from eight other children after they'd been diagnosed with retinoblastoma. The leukocoria is present in all of them.

Using the more than 7,000 pictures Bryan and Elizabeth have taken of Noah, the paper also shows that the amount of leukocoria that the digital cameras can detect increases with the size of his tumor.

Bryan is hoping to get more pictures from families with a child with retinoblastoma. He's also looking for a collaborator who could write software that would automate the process of scanning photos for leukocoria.

The disease is rare — fewer than 12 cases per million children aged 0-4. That works out to about 1 case for every 15,000 live births. Still, Bryan thinks a screening test would help with early detection of the cancer, and might save the vision of kids like Noah.

And speaking of Noah, he's a hoot. His health is good, and the cancers seem to have given up. He likes to draw and sing, and he's anything but shy. He has a prosthesis where his right eye used to be, which makes him look pretty much like any kid his age. And now he has a baby brother Samuel who, happily, doesn't share his disease.

View the original article here