Discovery News: Material World

Sheet of Tiny Antennae Harvest Sunlight and Heat

When you think of harvesting solar energy, most likely you think of solar cells, which convert sunlight into electricity.

But the sun is made up of a wide spectrum of light, and solar cells typically capitalize on only the visible light. Now researchers at the U.S. Department of Energy's Idaho National Laboratory have found a way to collect mid-infrared rays, which the planet radiates as heat. This kind of energy is not only produced constantly by the Earth after it absorbs sunlight during the day, but it's also generated by factories and coal-fired plants.

The researchers developed a thin plastic sheet containing billions of tiny nanoantennas that can harvest the mid-infrared rays. In addition to potentially harvesting energy radiating from the planet, the sheets could also work to absorb waste  heat and cool down buildings or electronic devices without air-conditioners and fans.

The nanoantennas are made from gold and set in a specially treated form of polyethylene, a material used in plastic bags. One square (at right) contains roughly 260 million antennae.

Modifying the antennae in size and shape allows them to pick up other wavelengths of light. This means that the sheets could be manufactured to have two sides -- each side harvesting energy from a different part of the sun's spectrum.

The plastic sheets could also be stamped with the gold antenna, the way newspapers are stamped with ink in a large printing press. That could make it cheap to manufacture large sheets that cover the roof of a building or form the skin of consumer gadget.

Photo courtesy Steven Novack, Idaho National Laboratory

Green Roofs, Warp Engines and Cheap Solar Power

These are the coolest stories I read this past week.

July 25 / Scientific American
Urban Roofscapes: Using "Wasted" Rooftop Real Estate to an Ecological Advantage
How a green roof can minimize run-off and mitigate the urban “heat island effect.”

July 25 / BBC
HP's Plan to Fix Ailing Planet
Trillions of sensors deployed worldwide will monitor the state of the planet and pick up ailments (wildfires, hurricanes, bacteria, hazardous chemicals) that may need to be warded off or remedied.

July 26 / The New York Times
China Surpasses U.S. in Number of Internet Users
Is anyone surprised? I'm so not surprised that I almost didn't put this on the list. You're right. I'm taking it off. 

July 28 / Discovery News
Warp Drive Engine Would Travel Faster Than Light
Gather 'round Trekkies. Your time has come. Two physicists have figured out warp drive works without breaking the laws (of physics, that is).

July 28 / Scientific American
Engineering Silicon Solar Cells to Make Photovoltaic Power Affordable
One company is on a mission to get the cost of solar cells down to a buck a watt. Those are light bulb prices that would make energy from the sun competitive with that from coal-burning power plants.

July 28 / The New York Times
Former Employees of Google Prepare Rival Search Engine
This company pronounces their name, Cuil, as "cool." That, and the fact that they are trying to upstage Google, makes me narrow my eyes with skepticism.

July 30 / Nature
Energy: Upgrading the Grid
What it takes to make a stupid power grid super smaht.

July 30 / Wired
Project to Rebuild Internet Gets $12M, Bandwidth
There's a project dedicated to rebuilding the Internet's underlying architecture? Whoa. I didn't even know about that.

July 30 / BBC
Olympic Link to Early 'Computer'
A closer look at an ancient Greek timepiece discovered in 1901 reveals that it has dials that record the dates of the original Olympic games.

July 31 / Technology Trends
OmegaTable, A 24-million Pixel VR Display
This virtual reality display is a multi-sensory touch tabletop that gives people a 3D experience without looking like a giant dork in those special glasses.

July 31 / Technology Review
3-D Printing for the Masses
This printing service takes orders from customers and turns ideas into three-dimensional prototypes at an affordable cost. If you're an artist, architect, designer, or general hobbyist, you might want to read this article.

July 31 / The Guardian
Sweet Peas Make a Second Skin
Didn't know this, but an enzyme in sweet pea pods and seeds can cause floppy skin in grazing animals. That's totally weird. But that same enzyme, when used in a polymer gel wound dressing, could relieve shrinking or lumpy skin grafts on burn victims.

July 31 / Economist
Genetically Modified Olympians?
You can detect performance-enhancing drugs, for the most part, but how do you detect gene therapy?

July 31 / New Scientist
Solar-Cell Material Can Soak Up More Sun
The sun cranks out a ton of energy, but conventional solar cells are only able to absorb the visible light part of the sun's spectrum. A new material that absorbs the infrared could, in theory take energy absorption from 30 percent to 63 percent.

Marine Worm Jaws Inspire New Aerospace Materials

Many researchers look to nature for design inspiration. For example, those working on micro air vehicles look to insects such as dragonflies; those working on climbing robots or adhesives look to the gecko lizard; and those working on making water-repellent or super clean surfaces look to the lotus plant.

So it shouldn't be a surprise, then, to hear that a worm has inspired scientists to consider new ways of making aerospace materials. But frankly it is. Especially from one that is as creepy-looking as this sandworm.

But truth be told, this little guy, Nereis virens, has a fang-like jaw that, in addition to helping it burrow into sediment, could serve as a model for a new class of super-strong, lightweight materials.

The scientists found that the creature's jaws are made up mostly of protein (about 90 percent). But it also contains a unique protein rich in the amino acid histidine as well as zinc, which works to strongly connect the proteins together. The bonds makes the jaw material three times harder and stiffer than any plastic we have now.

If we can copy the formula, say the scientists, we might be able to develop strong, lightweight materials for airplanes or spacecraft.

Atom-Fusing Laser, Robotic Jellyfish, Invisibility Carpet, A Pregnancy Gene and More

These are the coolest tech stories I discovered this past week.

July 12 / The New York Times
Can’t Find a Parking Spot? Check Smartphone
If you live a big city, then you know what it's like to drive around and around looking for that elusive parking spot. But starting this fall, San Franciscans will be in for a treat. The city is testing the use of wireless sensors that will communicate to street signs or a smartphone the availability of free spaces. Now just don't run anyone over trying to get the spot first.

July 13 / Guardian
Doctors Rage At Being Rated Online
As a big fan of AngiesList and Yelp, I'm all for a Web site that will allow patients to rate their doctors online. Isn't it all about referrals anyway? And health care is a service for which we pay big bucks. So suck it up, GPs, and get with the times.

July 15 / Discovery News
Giant Laser in the Works to Achieve Fusion
Wouldn't Dr. Evil love this "laser?" It can't blow up the planet, but at 10 stories tall and 400 feet long, it will create enough heat and pressure to fuse atoms and create helium. The reaction will release massive amounts of environmentally friendly energy and enough helium to keep us all talking about it with high squeaky voices.

July 15 / New Scientist
Dirt-Repelling Tube Promises Cheap, Pure Water
Man, we've really messed up the world's water supply. Most of it can't be consumed without being purified first, and that's not good for people living in developing worlds. But a a new way of purifying water could offer a simple solution. The technique uses a material that naturally attracts water while at the same time repelling impurities.

July 15 / BBC
The Importance of Being There
You have to really not like your surroundings (or yourself?) to prefer a virtual world over reality. But even still, VR environments have a long way to go before they will supplant this world, says regular columnist Bill Thompson.

July 16 / Wired
Obama Wages Cyberwar
Even though the Bush administration has initiated a $30 billion effort to beef up cyber security, Obama says its too little too late.

July 16 / Popular Science
Robotic Jellyfish Just Like the Real Thing, But Without the Sting
Sure, it's great that the AquaJelly has sensors, a short-range radio system, LEDs for illumination and communication and is coated with conductive metal paint that helps it connect with a nearby charging station, but I think they're dern pretty and I sure wish I had one. Hint hint.

July 16 / Wired
Army Wants 'Psychologically Inspired' Robot Vision
Robots score a big "duh" when it comes to vision. They just can't see the world we do. That's why the Army has put out an APB for a "psychologically inspired object recognition system." But do we really want robots seeing the world through our eyes? What if they notice what a bunch of doofuses we are?

July 17 / Discovery News
Invisible Carpet Idea Close to Actual Invisibility
Invisibility cloaks are great for hiding giant spaceships, but an invisibility carpet is just way more practical. Scientists have created a material that can hide objects in visible light. My question: If we can't see it, how will we know it's working? (See what I mean about being a doofus.)

July 17 / Popular Science
A Gene for Baby Makin’
This could put an end to birth control pills, foams and devices and eliminate the need for testicle snipping. Scientists have located the gene that both regulates and blocks ovulation.

July 17 / Wired
Why China's Olympian Efforts to Clean Up Beijing's Air Won't Work.
China is doing a bunch of stuff to clean up the air in time for the Olympics. Smoking bans, traffic bans and turning off power plants to name of few. But it might not make any difference.

Photo: Lawrence Livermore National Laboratory

Acoustic Cloak Good for Airport-based Blogging

My flight back to Boston is about 2 1/2 hours delayed. I have a nice chair and a pretty good view of the western sky, where the sun is melting like an orange popsicle down behind terminal C. I'm in no rush. For the most part, everything is fine. For the most part. Because three chairs down some 20-something, purple-hoodie-wearing, giggling manicure is chatting it up with her dorm buddy about dis and dat and I got 28 minutes left on my Boingo Wi-Fi.

Wouldn't an acoustic cloak come in handy right about now? (See also an article in Technology Review.) Made from artificial composites, or meta-materials, a cloak could be engineered to produce specific acoustical effects, some of those redirecting unwanted, annoying sounds. Practically speaking, such materials could be made into sound proof walls, for example, or "put a sock in it" quiet curtains.

In the words of the woman who could receive a free mini-sailboat with the purchase of Nupont fiber woven bowls, "I want that."

Photo: New Journal of Physics