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.

Yeon 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.

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

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

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.

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.

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

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

To help support themselves, the Huichol create beautiful artwork, including paintings made from yarn and sculptures made from beads. They sell their art in cities hundreds of miles away from their villages. Often, they travel long distances by foot. And without electricity—at home or on the road, they can only work during daylight hours.

Portable lights are bringing much-needed light to the Huichol people, who live in the beautiful and rugged Sierra Madre of Mexico.Huichol art is full of symbols and meaning. This traditional yarn painting (above) was made by Huichol artist Rojelio Beuites

Stephanie/Wikipedia

When it gets dark, they must stop whatever they’re doing, explains Huichol community leader Miquel Carillo. The sales of their artwork are essential to this economy, where farming is difficult and crops often fail.

“We can only work during the day,” Carillo tells a group of researchers as night approached. “Because now, as you see, we can’t see anything, and it’s still so early. Nobody can do anything. We just wait for the sun to come up again.”

Now, a team of scientists, designers, and architects is using new technologies to provide the Huichol with light after the sun sets—no plugs necessary. The scientists’ technique involves weaving tiny electronic crystals into fabrics that can be made into clothes, bags, or other items.

A Huichol woman weaves new, light-producing technology into a traditional cloth bag.

Kennedy & Violich Architecture, Ltd.

By collecting the sun’s energy during the day, these lightweight textiles provide bright white light at night. Their inventors have named the textiles “Portable Lights.”

Portable Lights have the potential to transform the lives of people without electricity around the world, says project leader Sheila Kennedy, head of Kennedy & Violich Architecture, Ltd., in Boston, Mass.

“Our invention,” Kennedy says, “came from seeing how we could transform technology we saw everyday in the United States and move it into new markets for people who didn’t have a lot of money.”

As part of the Portable Light Project, Kennedy and colleagues have already donated light-producing textiles to two Huichol communities. They are working now with a group of wandering, or semi-nomadic, people in Australia. Eventually, they hope to deliver Portable Lights to similar groups around the world.

See the light

At the core of Portable Light technology are devices called high-brightness light-emitting diodes, or HB LEDs. These tiny lights appear in digital clocks, televisions, streetlights, and the blinking red lights on some sneakers.

LEDs are completely different from the light bulbs that you screw into lamps at home. Most of those glass bulbs belong to a type called incandescent lights. Inside, electricity heats a metal coil to about 4,000 degrees Fahrenheit, or 2,200 degrees Celsius. At that scorching temperature, bulbs give off light we can see.

In an incandescent light bulb, like the one above, electricity heats a metal coil until it becomes extremely hot and gives off light.

Wikipedia/Tomasz Sienicki

Ninety percent of energy produced by incandescent lights, however, is heat–and invisible. With all that wasted energy, bulbs burn out quickly. They are also bulky, can get hot, and are easily broken.

LEDs, on the other hand, are like tiny pieces of rock made up of molecules that are arranged in a crystal structure. When an electric current passes through an LED, the crystal structure vibrates and produces light.

Unlike incandescent bulbs, they can produce light of various colors. Within an LED, the type of molecules and their particular arrangement determines what color is produced.

For example, green LEDs make up the blinking, hand-shaped signals that tell pedestrians when it’s safe to cross a street. LEDs in a remote control, on the other hand, give off invisible infrared light that tells a television to change channels.

Light-emitting diodes come in a variety of sizes and colors. What they all share in common is their tiny size compared to incandescent bulbs. The purple-colored LED in the lineup above emits infrared light.

Wikipedia

LEDs are tiny and extremely lightweight. There are no breakable glass parts. While the technology is still somewhat expensive, researchers are increasingly looking to LEDs for a wide variety of applications, including Portable Lights.

“A lot of people see LEDs as being the future of lighting,” says Casey Smith, a technologist in Bozeman, Mont., and a member of the Portable Light team. He developed much of the technology that make Portable Lights work.

The spark

The Portable Light team found a way to weave two LEDs into a plastic-coated textile. When turned on, these LEDs can make the entire piece of fabric glow.

Their next challenge was to figure out how to power the LEDs without electricity. The researchers knew that they wanted to tap the sun’s energy, but they couldn’t use standard solar panels such as those found on rooftops. These bulky glass panels would be too big and heavy for the Huichol to carry as they traveled through the mountains.

Instead, the researchers used a new type of solar panel, which is flat and flexible, like a placemat. Just 10 inches long and 5 inches wide, these panels can be easily sewn onto a piece of fabric.

A Mexican boy who lives in the Sierra Madre carries a woven bag, complete with LED’s and a solar panel.

Kennedy & Violich Architecture, Ltd.

Circuits connect the solar panel to a lithium ion battery—the type of battery found in laptops and cellular phones. And the battery, in turn, is connected to the two LEDs in the fabric. A tough layer of plastic protects the circuitry.

With just 3 hours of exposure to sunlight, the battery accumulates enough charge to power a portable light for 10 hours, Kennedy says. A membrane switch, like the soft buttons on a microwave oven, allows a user to turn the lights on or off.

Portable light technology provides enough light for this Huichol girl to do her homework at night, even though there is no electricity in her village.

Kennedy & Violich Architecture, Ltd.

A Portable Light weighs less than a pound and can withstand abuse because textiles are strong for their weight. Kennedy has dropped Portable Light units from as high as 30 feet off the ground without damaging them.

“With no heavy parts to break, they just float down,” she says.

Lighting the way

The Huichol have quickly accepted Portable Light technology by incorporating it into their cultural traditions.

Huichol women have long woven colorful bags on a handmade device called a backstrap loom. They use these bags to tote their belongings because their traditional clothing does not have pockets.

Each bag contains intricate patterns and symbols that reflect cultural stories and family identities. Bags and patterns are passed from generation to generation.

“It is more than just a bag,” Kennedy says. “It is vital to their life.”

Portable lights are bringing much-needed light to the Huichol people, who live in the beautiful and rugged Sierra Madre of Mexico.

Tim&Annette/Wikipedia

The Huichol are now weaving Portable Lights into new patterns in their bags, Kennedy says. And the researchers on the Portable Light team can’t keep up with demand. More than 40 women have put their names on a waiting list.

On the other side of the world, in the Central Australian desert, Kennedy and colleagues are working to bring Portable Lights to the Arrernte people, who travel across large stretches of desert without electricity.

One goal is to use the technology to power cell phones that teachers in local schools can use to download lesson plans. That way, Kennedy says, kids won’t have to travel to cities to get an education.

It may be hard to imagine life without access to lights at night. As the Portable Light project expands, researchers hope that fewer and fewer people will have that problem.

Additional Information

Questions about the Article

Word Find: Night Lights

Going Deeper:

Government and utility officials are still scrambling to explain a blackout that hit much of the northeastern United States in late summer. From Detroit to New York, lights went out. Refrigerators, traffic signals, elevators, and subway trains stopped working. Computers went dead.

Lightning over a darkened city.

Without electricity, people had trouble getting to work, shopping for groceries, and communicating with each other. Normal life pretty much shut down for a few days.

Electricity also plays a crucial role within the human body. A lightning bolt or shock can disrupt or shut down that flow, causing disability or death.

“Electricity is life,” says David Rhees, executive director of the Bakken Library and Museum in Minneapolis. The Bakken museum is dedicated entirely to the history and applications of electricity and magnetism in biology and medicine.

The museum has a lot to keep up with. As scientists learn more about the electrical signals that whiz through our bodies and the electrical pulses that tell our hearts to beat, they are finding new ways to use electricity to save lives.

Research on the nervous systems of animals and people are helping scientists design machines that help diagnose and treat brain conditions and other problems. New drugs are being developed to regulate the body’s electrical pulses when things go wrong in response to injury or disease.

Electricity everywhere

Electricity is everywhere, thanks to the unique structure of the universe. Matter, which is basically everything you see and touch, is made up of tiny units called atoms. Atoms themselves are made up of even tinier parts called protons and neutrons, which form the atom’s core, and electrons, which move around outside the core.

Protons have a positive electrical charge, and electrons have a negative electrical charge. Normally, an atom has an equal number of electrons and protons. The positive and negative charges cancel each other out, so the atom is neutral.

When an atom gains an extra electron, it becomes negatively charged. When an atom loses an electron, it becomes positively charged. When the conditions are right, such charge imbalances can generate a current of electrons. This flow of electrons (or electrically charged particles) is what we call electricity.

The first person to discover that electricity plays a role in animals was Luigi Galvani, who lived in Italy in the late 18th century. He found that electricity can cause a dissected frog’s leg to twitch, showing a connection between electrical currents traveling along an animal’s nerve and the action of muscles.

Quick signals

All animals that move have electricity in their bodies, says Rodolfo Llinas, a neuroscientist at New York University’s School of Medicine. Everything we see, hear, and touch gets translated into electrical signals that travel between the brain and the body via special nerve cells called neurons.

Electricity is the only thing that’s fast enough to carry the messages that make us who we are, Llinas says. “Our thoughts, our ability to move, see, dream, all of that is fundamentally driven and organized by electrical pulses,” he says. “It’s almost like what happens in a computer but far more beautiful and complicated.”

By attaching wires to the outside of the body, doctors can monitor the electrical activity inside. One special machine records the heart’s electrical activity to produce an electrocardiogram (EKG)—strings of squiggles that show what the heart is doing. Another machine produces a pattern of squiggles (called an EEG) that represents the electrical activity of neurons in the brain.

This recording of brain waves, called an EEG, represents the electrical activity of neurons in the brain.

One of the newest technologies, called MEG, goes even further. It actually produces maps of magnetic fields caused by electrical activity in the brain, instead of just squiggles.

Recent observations of patterns of nerve-cell action have given scientists a much better view of how electricity works in the body, Llinas says. “The difference between now and 20 years ago is not even astronomical,” he says. “It’s galactic.”

Now, researchers are looking for new ways to use electricity to help people with spinal injuries or disorders of the nervous system, such as Parkinson’s disease, Alzheimer’s disease, or epilepsy.

People with Parkinson’s disease, for example, often end up having tremors and being unable to move. One type of treatment involves drugs that change the way nerve cells communicate with each other. As part of another new treatment, doctors put tiny wires on the head that send electrical impulses into the patient’s brain. “As soon as you put that in,” Llinas says, “the person can move again.”

Philip Kennedy at Emory University in Atlanta has even invented a kind of “thought control” to help severely paralyzed people communicate with the outside world. His invention, called a neurotrophic electrode, is a hollow glass cone filled with wires and chemicals. With an implanted electrode, a patient who can’t move at all can still control the movement of a cursor across a computer screen.

Looking to the past

One way to help keep the medical field speeding into the future might be to cultivate an appreciation for the past. At least, that’s what the folks at the Bakken museum think.

Modern-day medical equipment powered by electricity.

When I recently visited the museum, Rhees and Kathleen Klehr, the museum’s public relations manager, took me down to a huge padlocked room in the basement called “The Vault.” Row upon row of shelves were crammed with rare, old books about electricity, early versions of pacemakers and hearing aids, and all sorts of weird devices. One was a shoe-store X-ray machine, powered by electricity, that showed you whether your foot fit comfortably into a new shoe.

Upstairs, the exhibits included a tank of electric fish and Hopi dolls dedicated to the spirit of lightning.

There’s also a whole room dedicated to a monster made famous in a book titled Frankenstein. Made from assorted human parts, the monster was brought to life by an electrical spark. When Mary Shelley wrote Frankenstein in 1818, electricity was still a relatively new idea, and people were fascinated by the possibilities of what they might be able to do with it.

Even today, the Frankenstein room, with its scary multimedia presentation, remains one of the Bakken’s most popular exhibits, Klehr told me. “It’s been centuries,” she says, “and everyone is still excited about Frankenstein.”

That’s something you might keep in mind the next time a blackout strikes. Without electricity, those monsters under your bed might have a lot less power over you!

Going Deeper:

Additional Information

News Detective: Emily goes to the hospital

Word Find: Spark of Life

Questions about the Article