Getting startedYeon Sik Jung puts chemicals onto a silicon wafer at start of an experiment in the clean room. Credit: D. Fox

Watching Yeon Sik Jung’s slow, careful movements, you sense that he’s doing something important. But it’s way too small to see.

Jung (pronounced Yoong) is dressed in white from head to toe. He wears a white jumpsuit, white boots, a white mask with goggles and a white cap on his head.

With a white-gloved hand, Jung lifts an eyedropper and squeezes liquid onto a flat, shiny disk. That glistening drop hides an invisible world. And Jung controls that world. Within, he is creating some of the smallest electric circuits ever made.

Jung works at Lawrence Berkeley National Laboratory’s Molecular Foundry, just outside Berkeley, Calif. A foundry is a place where tools and other parts are made out of metal. Molecules are tiny building blocks in everything from snot to snails to you and me. Put the two words together, and you have a place where scientists use molecules like Legos to build things too small to see.

Jung is currently working on an invention that could help us overcome the challenges of global warming. Another scientist, named Xiaogan Liang (pronounced Lie-Ang), stands nearby. The two scientists are trying to build tiny electrical circuits called solar photovoltaic cells within the drop of liquid. Solar cells can turn sunlight into electricity.

Filthy people

Jung, Liang and I have to wear these white suits, called “bunny suits,” because we’re in a special room called the clean room.

You may not realize it, but people are filthy—even after a bath. Your body constantly sheds flakes of dead skin. Your clothes, hair and shoes let specks of dust loose into the air. Every breath that you inhale contains more than 20,000 pieces of this invisible garbage, twirling around like loose leaves on a windy autumn day. That tiny trash doesn’t usually hurt your lungs, but it would ruin the work that Liang and Jung are trying to do.

Compared with the tiny things that Liang and Jung are building, a single flake of dandruff is huge. “A speck of dust would be like a comet,” says Liang, referring to the huge chunks of ice that fly through space. A comet hitting Earth could destroy a city, and a piece of dust landing in Jung’s little drop of liquid would ruin his miniature world, too.

So we have to cover our filthy selves in these suits. Pumps filter the air to remove any stray bits of dust. No eating or drinking is allowed. We’re not even supposed to fart. “In principle, it is not desirable to do that,” says Liang in a careful, scientific tone. “But we don’t have detectors in here.”

Every rooftop

As Liang talks, Jung lets the drop of liquid spread out on the shiny, mirror-like disk, called a wafer. Then he sets it in an oven heated to 200º Celsius. “That’s it,” says Jung through his mask. “We just need to wait a couple of hours.”

Today’s experiment is so simple that it’s almost boring to watch. But if Jung, Liang and other scientists succeed, their work could ultimately allow people to put solar photovoltaic cells on every rooftop in thousands of cities around the world, which would help reduce the amount of coal, oil and natural gas burned. That, in turn, would reduce the amount of Earth-warming carbon dioxide pumped into the air.

For a long time, photovoltaic cells have been made from a mineral called silicon. To make pure silicon, scientists actually have to melt sand or rock. It means heating the rock to more than 1,000º C—pretty much what a volcano does. And then scientists have to heat the purified silicon again, to 600º C, so it will form pure crystals. “That takes a lot of energy, and energy costs money,” says Larry Kazmerski, an electrical engineer at the National Renewable Energy Laboratory in Golden, Colo. After that, expensive robotic machines have to build patterns onto the silicon. “The processing is very involved and complex.”

So even though photovoltaic cells could help people burn less coal, oil and natural gas, they cost so much that few can afford to buy them. Even today, 40 years after the first photovoltaic cells were invented, few roofs have them.

Nanoscience, the science of very small things, could solve that problem. The term “nano” means one billionth. The term “nanometer” means one billionth of a meter—or about one billionth the length of a baseball bat.

Greasy frying pan

FocusXiaogan Liang works with the “focused ion beam” instrument in the clean room. Credit: D. Fox

Liang, Jung and other nanoscientists are coming up with a new way to build really small things without the need for such high heat and without the help of the expensive robots. The process is called “directed self-assembly,” and it’s surprisingly simple.

You mix a couple of chemicals together, put a drop of the liquid onto a piece of silicon or plastic (it doesn’t really matter what), and then those chemicals do the work for you. As the chemicals dry, the individual molecules arrange themselves into a complicated pattern, like the pattern that your grandmother might stitch on a quilt. For the photovoltaic cells, Liang and Jung want to create row after row of evenly spaced pencils that will stand up like spines on a porcupine.

If you’ve ever watched a frying pan full of grease cool off, then you’ve seen a very simple kind of self-assembly. As the pan cools, the grease forms little round droplets that sit on top the water in the pan. It happens automatically because of the way that grease and water molecules interact with each other.

Another kind of self-assembly happens when snow falls during winter. All by themselves, water molecules latch together to form beautiful, complicated six-pointed stars of ice — snowflakes. Snowflakes are so complicated that you could never cut a real one out of construction paper using scissors. And yet the mindless little molecules do it themselves.

So what if you could learn to make the molecules do what you want them to? What if you could mix two chemicals so the molecules arranged into specific shapes? What if you could control those patterns just by choosing one chemical or another? Depending on the chemicals you mixed, you might get a polka-dot pattern. Or perfectly straight pinstripes. Or spirals. Or a crisscrossed honeycomb, like in a beehive.

Liang, Jung and their boss at the Molecule Foundry (a scientist named Deirdre Olynick) are learning the art of self-assembly. They can create all of those patterns by choosing the chemicals to mix together. Today in the lab, Liang and Jung are making tiny pegs like pencils standing straight up. If it works correctly, each pencil will be exactly the same size, about one ten thousandth as wide as the sharp point of a safety pin.

Interlocking fingers

Solar cells are made of two types of material, one stacked on top of the other. When sunlight hits the cells, it knocks electrons from one layer into the other—creating electricity. (Electricity is the movement of these tiny charged electrons.) Those two layers could sit flat on top of each other, like layers in a birthday cake. But the solar cell works better if the two layers interlock. With an interlocking pattern, the two layers touch each other over more area. It gives the cells a better net for catching sunlight, and they can convert more of the sunlight into electricity. Those tiny pencils that Liang and Jung are making will be the first step in creating layers that interlock like fingers.

Close-up viewXiaogan Liang looks at the self-assembled projects under the electron microscope in the clean room. Credit: D. Fox

Self-assembly avoids the high temperatures used in making pure silicon. Never mind volcano temperatures reaching 1,000º C. Jung and Liang are cooking their drop of liquid at just 200º C—about as hot as pizza is cooked. And because the molecules arrange themselves, Jung and Liang also should not need as many expensive robotic machines to make the complicated patterns that will interlock the two layers in their solar cells.

The big challenges in self-assembly are being clean and using the right recipe. And the recipe that Jung and Liang are using today is simpler than making pizza.

“That’s the point,” says Stefano Cabrini, the director of the Molecular Foundry. “The point of self-assembly is to make something easily that you can produce many, many of.”

Invisible forest

After waiting two hours for the chemicals to bake and dry, Liang and I slip back into our bunny suits and return to the clean room.

As Liang lifts the wafer with a pair of tweezers, it’s hard to see any difference. The wafer looks shiny, just like before. The coating of chemicals on the wafer is very thin—only one ten-thousandth as thick as a sheet of aluminum foil.

In order to see the pattern that those molecular Lego blocks have formed, we need to look at it through a special microscope, called an electron microscope. This microscope is the size of a small refrigerator, with wires coming out on all sides. The picture from the electron microscope shows on a computer screen.

As Liang turns knobs to focus the microscope, a hidden world takes shape.

On the screen we see what looks like a forest of gray pencils standing straight up. If we were looking at red blood cells or little amoebas swimming in pond water, we might need to magnify the picture only 200 times. But in order to see this hidden forest of pencils, Liang has magnified the picture 590,630 times.

Each one of those pencils is only 60 atoms across. Even the most advanced silicon-carving robots today cannot carve shapes this small. But here, the researchers have done it just by mixing a couple of chemicals together. Shake and bake.

Printing money

This pencil-studded wafer that Liang and Jung have made could someday be used to print solar cells onto sheets of plastic, the same way that dollar bills are printed onto paper.

In the factory, a sheet of plastic might roll off of a giant spool. As the sheet of plastic moves, like a conveyor belt, a huge printing press would squish down on it. That printing press would have the same tiny pencil-studded pattern that Liang and Jung made today. It would press that shape into the plastic—“like kids making handprints in the mud,” says Liang. Then another chemical could be painted over the top of the plastic sheet, filling the holes made by the tiny pencils in the printing press and creating a second layer. And abracadabra—you would have a sheet of photovoltaic cells. That sheet would be rolled like toilet paper onto another huge spool.

When people build a house, they could go to the store and buy a few rolls of that solar cell paper. They’d unroll the cells onto the roof of their houses. Unlike toilet papering a house, though, this would be good for the environment. Those solar cells would convert sunlight into the electricity needed to turn on lights and run computers.

If this self-assembly works, it could allow many more people around the world to put solar cells on their buildings. “There is risk. There’s no guarantee it will work,” says Kazmerski. “But the benefit is quite incredible. It could revolutionize [solar power] very quickly if it’s successful.”

Lots of other nanoscientists around the world are working on different kinds of self-assembly. If they succeed, then self-assembly could eventually be used for making many other things, like the tiny electrical chips that run computers and iPods and radios. Self-assembly might allow scientists to make all of these things smaller than ever before. Years from now, an iPod might be the size of a dime.

These are the hopes of nanoscience, at least. Finding out whether they happen will take years of hard work. Scientists like Liang and Jung can look forward to spending a lot more time in their bunny suits.

POWER WORDS

Atom – The basic structure of a chemical element. Atoms have a nucleus that contains protons and neutrons and is surrounded by electrons that move around it in orbits at high speed. When atoms combine together they form molecules.

Bunny suit – A white suit that is worn in a clean room to prevent dirt and flakes of skin from interfering with experiments.

Chemical compound – A substance made of atoms of two or more chemical elements that are combined in molecules.

Chip – A complex electric circuit that is etched onto a tiny slice of material called a semiconductor. Chips are used in computers and most electronic devices and may contain tiny switches, capacitors and other devices.

Circuit – A closed path through which an electrical current flows. Circuits have a source of electricity, such as a battery or generator, and a wire that connects the source to a part that uses the electricity, such as a lamp or television.

Clean room – A room used in laboratory work that is kept virtually free of contaminants such as dust and bacteria.

Comet – A mass of ice, frozen gases, and dust particles that travels around the Sun in a long path.

Electricity – A form of energy produced by particles that have charge, especially electrons. Electricity can flow in an electric current, or it can be static.

Foundry – The building and works for casting metals.

Magnification – A number that shows how many times larger an object looks than it really is.

Microscope – An instrument that makes very small objects appear larger.

Electron microscope – A very powerful microscope that uses a beam of electrons, instead of light, to magnify objects that are too small to be seen with an ordinary microscope.

Molecule – A group of two or more atoms that are joined together by sharing electrons in a chemical bond.

Nanometer – One billionth of a meter.

Nanoscience – The study of things at the ultrasmall scale, usually a hundred nanometers or less.

Photovoltaic cell – A device that changes sunlight into electricity. Solar cells are used to supply power to satellites, calculators and other devices.

Printing press – A machine that uses contact to transfer letters or images onto paper.

Red blood cell – A cell that is shaped like a disk and is found in the blood of humans and other vertebrates.

Self-assembly – A process by which disorganized, disordered components create on their own some organized structure or pattern.

Silicon – A chemical element that makes up about one-fourth of the Earth’s crust.

Solar energy – Energy that comes from the sun’s radiation. Solar energy can heat up rooms that have windows facing the sun and can also be used to make electricity in solar cells.

Why are these scientists smiling? Professors Yet-Ming Chiang, Angela Belcher and Paula Hammond from MIT proudly stand with a battery-building virus they have engineered. The virus is on a glass slide held by Belcher, center.

What do chicken pox, the common cold, the flu, and AIDS have in common? They’re all diseases caused by viruses, tiny microorganisms that can pass from person to person. It’s no wonder that when most people think about viruses, finding ways to steer clear of viruses is what’s on people’s minds.

Not everyone runs from the tiny disease carriers, though. In Cambridge, Massachusetts, scientists have discovered that some viruses can be helpful in an unusual way. They are putting viruses to work, teaching them to build some of the world’s smallest rechargeable batteries.

Viruses and batteries may seem like an unusual pair, but they’re not so strange for engineer Angela Belcher, who first came up with the idea. At the Massachusetts Institute of Technology (MIT) in Cambridge, she and her collaborators bring together different areas of science in new ways. In the case of the virus-built batteries, the scientists combine what they know about biology (the study of living things), technology and production techniques.

Belcher’s team includes Paula Hammond, who helps put together the tiny batteries, and Yet-Ming Chiang, an expert on how to store energy in the form of a battery. “We’re working on things we traditionally don’t associate with nature,” says Hammond.

Professor Angela Belcher shows off the virus-built battery she helped engineer. The battery — the silver-colored disk on the right side of the device — is being used to power an LED.

Donna Coveney/MIT

Many batteries are already pretty small. You can hold A, C and D batteries in your hand and the coin-like batteries that power watches are often smaller than a penny. However, every year, new electronic devices like personal music players or cell phones get smaller than the year before. As these devices shrink, ordinary batteries won’t be small enough to fit inside.

The ideal battery will store a lot of energy in a small package. Right now, Belcher’s model battery, a metallic disk completely built by viruses, looks like a regular watch battery. But inside, its components are very small—so tiny you can only see them with a powerful microscope.

How small are these battery parts? To get some idea of the size, pluck one hair from your head (unless that seems too painful). Place your hair on a piece of white paper and try to see how wide your hair is—pretty thin, right? Although the width of each person’s hair is a bit different, you could probably fit about 10 of these virus-built battery parts, side to side, across one hair. These microbatteries (“micro” means very small) may change the way we look at viruses.

Slimy liquids that pack a punch
The word “virus” comes from a Latin word that means “poison” or “slimy liquid.” Each virus has a name, and the virus used by Belcher and her team is called M13. To humans, the M13 virus is actually harmless. The virus only infects bacteria. Under a powerful microscope, the M13 virus looks like a thread.

A virus usually has two main parts: a shell and genetic material, molecules called nucleic acid, inside the shell. You can think of nucleic acid (which can be DNA or RNA, depending on the virus) as a recipe that tells the virus what to do. Every living cell has a recipe inside—the genetic material inside you, for example, tells your cells how to keep you alive and functioning.

A virus is like a switch. When a virus is by itself, it cannot do anything—it is switched off. Its genetic recipe sits quietly. The virus cannot reproduce, spread or do any harm. A virus becomes harmful only when it gets inside the cell of a living organism—at this moment it switches “on.” For example, if you look at the chicken pox virus under a microscope, it can’t hurt you. But if the virus finds its way into your body, look out—and try not to scratch.

You won’t see it coming: When the genetic material inside this influenza virus gets into your cells, you get the flu. This picture was taken with a powerful microscope.

CDC/ Dr. Erskine. L. Palmer; Dr. M. L. Martin

When a virus attacks a cell, the virus injects its genetic material inside. The viral genetic material takes over the cell, pushing aside the instructions from the cell’s own genetic material. Instead of doing its normal functions, the cell starts to make copies of the virus. In other words, the virus cannot reproduce itself, but it can turn a living cell into a virus-making factory. These new virus particles can break out of the cell and go on to attack other cells. Those cells may make more virus particles. An infection is born.

Viruses only function inside another cell, so are viruses alive? Scientists have debated this question for decades, and your answer depends on how you define “alive.” On one hand, you might say that something is alive because it has genetic material. Human beings and animals, for example, have genetic material. Rocks do not. On the other hand, if you say that something is alive only if it is able to reproduce and store energy, then viruses are not alive because they need hosts. They’re on the line between living and nonliving things in the world—more like zombies than living organisms!

Changing the recipe
Remember that when a virus invades a cell, it forces the cell to start making new virus particles. At MIT, the scientists are turning that relationship on its head. Belcher and her team are able to go inside the virus and change its genetic recipe. With these changes, the scientists turn the tiny foe into a useful friend.

Instead of attacking other cells, the altered virus does something no natural virus would do: It starts to collect little bits of metal on its shell. Soon the virus is covered by a tiny suit of armor. Underneath the metal, the virus is still there. Belcher likens the virus to a scaffolding—the support structure you might see outside a building that is under construction. The virus provides the structure, giving form to the metal parts while the parts are being put together.

The slide in this picture contains the electronic circuitry that Belcher used to test her virus-built battery. The battery is so small you can’t see it, but it’s there.

Belcher Laboratory, MIT

“The virus remains intact, but is completely covered,” Belcher says.

This metal structure plays an important part in the battery. After the battery charges and discharges, she says, the virus itself may break down, but the metal structure will remain.

A battery is made of three main parts: two electrodes and an electrolyte. Electrodes are pieces of metal with electric charges, and an electrolyte is a material between them. You might think of a battery as a peanut butter sandwich, where the metal electrodes are like the bread and the peanut butter is the electrolyte. (For more information, see What is a Battery? below.)

The metal collected by the virus can be used as an electrode. In 2006, the team built only one electrode, but their research has advanced quickly since then. “We have the materials where we can make the full microbattery now as well,” Belcher says. Last year, together with Hammond and Chiang, she showed how the virus-built electrodes can be produced quickly and cheaply, without toxic chemicals. And earlier this year, with another team of engineers, she helped design the other electrode. When Belcher’s team tested the new, complete battery in the laboratory, it performed as well as other rechargeable batteries.

The microbatteries could be used to power a wide variety of tiny electronic devices. “Because [the batteries] are very small, they can be implemented into anything that involves microfabrication,” says Hammond.

In addition to the ever-shrinking world of electronics, the batteries may also play a role in the search for alternative energy sources. One reason we don’t see more electric vehicles on the road is that they require many heavy batteries to operate. If Belcher, Hammond and Chiang’s work is any indication, then lighter, more efficient batteries aren’t too far away. Just think—the batteries in your car may one day be built with help from a virus!

Going Deeper:

Angela Belcher and her team are currently trying to teach viruses to build new solar cells. To keep up with the latest from her lab at MIT, go to http://belcher10.mit.edu/

Paula Hammond’s research group puts together some of the smallest things in the world: http://web.mit.edu/hammond/lab/

Yet-Ming Chiang’s batteries are making the world a greener place: http://web.mit.edu/INVENT/iow/ychiang.html

When it comes to lighting, though, we’re stuck in the past. The incandescent light bulb that you probably have in your bedside lamp is based on the same technology invented by Thomas Edison more than a century ago. Electricity flows into a metal filament, and the filament heats up and emits light as a byproduct.

Now, the same technology that forms the basis for our computers is set to revolutionize electric lighting as well. It’s known as solid-state lighting, and it has the potential to transform the way we use light.

Light from Computers

Computer chips are made up of what are known as semiconductors. These are solid materials (such as silicon) that can carry an electrical current but, unlike regular conductors like copper wire, can also be easily turned off so that electricity will not flow through it.

LEDs and their organic cousins, OLEDs, will one day make our homes and offices much brighter, while using less energy.

RPI Lighting Res. Center

Solid-state lighting includes two similar technologies: light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs). A diode is a simple form of a semiconductor, so both LEDs and OLEDs are like tiny computer chip parts that give off light.

Both technologies are composed of layers: one is negatively charged, and one is positively charged. When electric current flows through the diode, it excites negatively charged particles, or electrons, in one layer and causes them to fall into holes in the other layer. The energy released in that fall is emitted as light. The color of the LED depends on the material used in the layers and the distance the electrons fall.

Why LEDs?

We don’t think about it much when we flick on the lights, but keeping our houses lit uses up roughly 10 percent of all the electricity we use in homes. Add the lighting needs of businesses and the percentage is even higher. Incandescent light-bulbs are horribly inefficient: only about 5 percent of the energy goes into creating light. The rest is wasted as heat. Fluorescent bulbs are more efficient and last longer, but the toxic mercury in the bulbs means they have to be thrown out in special collections.

Depending on the color, LEDs are 20 to 50 percent efficient, so they save a tremendous amount of energy. The rest of the energy becomes heat, but they’re not hot to touch like incandescent bulbs. Researchers at Sandia National Lab estimate that within a little more than a decade, LEDs could cut the energy used for lighting in half!

LEDs also produce more than 70,000 hours of light — they last a long, long time. And they’re encased in plastic, not glass, so they’re nearly impossible to break.

These digital lights have already replaced traditional bulbs in traffic lights and in displays on clocks and cell phones. They’re used to colorfully light up bridges at night, and for larger-than-life videos, such as the enormous sign that hangs on the corner of a building in New York’s Times Square.

White LEDs are still too expensive to replace all our home and office lighting. But they make great camping flashlights, because they’re bright, tiny, energy-efficient, long-lasting, unbreakable, and can be powered by rechargeable batteries.

Many poor people around the world have no electricity in their homes, so they rely on expensive and polluting kerosene lamps. The same characteristics that make LEDs perfect for camping lights also make them ideal an ideal way to provide light for families who have never owned a bulb.

Groups such as the Light up the World Foundation have designed LEDs, powered by renewable energy, for people who lack electricity. Suddenly, children can study at night, and parents can keep working into the evening. LEDs have already improved the lives of thousands of people around the world!

The firm Kennedy and Violich Architecture created a fabric woven with tiny LEDS for a community in Mexico. It can be worn as a bag during the day, and turns into a lamp at night. (Read more about how it works here.)

New Ideas in Lighting

Imagine a room where you could push a button and change the color of the light. LEDs come in red, green and blue. Each one can be the size of a dot, and when those dots are combined, they can be lit up in different combinations to create an endless variety of colors. Companies have created LEDs that flow from one color to another, all through the rainbow.

“With the touch of a button you can create pretty much any color scheme,” explains Nadarajah Narendran, research director at the Lighting Research Center of Rensselaer Polytechnic Institute. “You could change the color in your room to suit your mood.”

Designers are developing new ways to use LEDs in a building. Light glows from a tile on the floor, or a panel on the wall. (This is hard to do with the breakable glass bulbs used today.) These tiles have already been built, but they don’t fit the standard systems in houses today, where bulbs get screwed into sockets. Narendran says that houses would have to be designed differently to create the right wiring for these blocks of light. He has some lighting up his lab!

But the uses of LEDs don’t end with indoor and outdoor light. Babak Parviz, a scientist at the University of Washington, is designing special lenses that use dust-sized particles of LEDs to display information. Parviz wants to create futuristic contact lenses that could sense changes in your body, such as from a disease, and notify you on the corner of the lens. These don’t exist yet, but someday you might be able to read information broadcast by LEDs literally right in front of your eyes.

LEDs, the Next Generation

LEDs are manufactured in the same manner as computer chips. The materials are deposited in very thin layers under extremely hot temperatures, as high as almost 1,000 degrees Fahrenheit. That costs a great deal of money. They’re also based on the material silicon, the same material that forms the basis for computer semiconductors.

OLEDs function similarly to LEDs, however, they can be manufactured much more easily; use even less power, and can be made extremely thin to be used on paper or even fabric.

Yogurt6255520 / Wikimedia Commons

Organic LEDs (OLEDs), on the other hand, have a carbon base instead of a silicon base. (Carbon forms the building-blocks of life on earth, which is why these are called “organic.”)They work in somewhat the same way as LEDs do: a current flows into the material, one layer gives off electrons, and those electrons fall into another layer. Then there’s a layer that transmits that energy into light we can see. The color of the light depends on the material in that final layer, and most OLEDs have different layers that emit different colors.

Unlike those super high LED manufacturing temperatures, OLEDs can be created at room temperature, which is significantly cheaper. Layers are deposited on a surface, as ink is layered on paper. OLEDs are also extremely thin and can be potentially printed on any substance, even paper or fabric.

“This flexibility is what makes people dream about all the different ways to use OLED technology,” says Bernard Kippelen, an OLED researcher at the Georgia Institute of Technology in Atlanta.

With OLEDs, Narendran imagines entire wall-sized sheets. He says, “You could hang one up and change lighting designs easily, like a shifting wallpaper of light design.” Because OLEDs are transparent when they’re off, a window covered by an OLED could glow brightly when night comes. Or a shimmering picture could be printed directly on a T-shirt.

OLEDs are used today in cell phone screens, but most of those other ideas are still in the design phase. Recently, though, Sony showed off the world’s very first OLED television. It’s only 11 inches large, and it costs about $2,500. It’s incredibly thin, only 3 millimeters at its widest spot — thinner than your finger from front to back — and uses about 40 percent less energy than other thin-screen televisions. The colors and picture are said to be some of the best yet. But with an expensive price-tag, and because it can’t yet be easily scaled up into a bigger screen, it may take years before you buy an OLED TV for the living room.

The path ahead

There are still challenges to overcome before solid-state lighting replaces all the bulbs in our sockets. Scientists are investigating ways to make both LEDs and OLEDs still more efficient and cheaper. The organic materials in OLEDs are fragile and don’t last as long as traditional LEDs, so scientists are looking for ways to make them sturdier. Plus, moisture harms OLEDs, so researchers are trying to figure out how to protect these lights of the future.

Kippelen says the scientists at his lab, like others around the world, are the innovators who are advancing the technology. But as for all the potential uses, Kippelen says, “I leave it to artists and designers to predict what can be done.”

Going Deeper: