What are some interesting innovations in science

Innovations: Nine ideas that could change the world

It is only in the last two years that battery electrodes have become sufficiently powerful to convert such differences between low temperatures into electricity. And before the process is ready for the market, some development work is required, explains Yang. But over time, batteries in series could adorn the walls of factory chimneys or power plants, converting low-quality waste heat into electricity. "It's interesting because this previously inferior heat is everywhere," Yang concludes. (Ryan Bradley)

8. Video cameras for nanoparticles

Nanometer resolution electron microscopes are widely used, but they cost millions of dollars and preparation of a viewing sample is cumbersome. Although this current state is sufficient for a laboratory, it makes industrial applications impractical - for example, quickly scanning product samples to look for embedded microscopic watermarks. A new type of holographic microscopy developed by David Grier of New York University and his colleagues could offer a solution. The team replaced the brightly shining light source of a commercially available Zeiss microscope with a laser and used it to illuminate the examination object: Light scatters from the sample and creates a three-dimensional interference pattern between the laser beam and the scattered light - a hologram, which is then recorded by a video camera.

Scientists have been making holograms of microscopic objects for decades, but it has always been difficult to extract useful information from them. And this is exactly where Grier's invention gains in value. His research team created software that was able to solve equations for unknown parameters as quickly as possible, such as how light is scattered by a spherical object. These parameters contain all possible useful information about the object causing the scattering. The microscopic resolution in the nanometer range enables researchers to detect particles floating in colloidal solutions (for example, nanoscale spheres floating in a color sample). To do this, they use devices that are only a tenth of the cost of an electron microscope.

Grier hopes that his device will be the first fast and affordable application with which one can look at individual particles in the core of modern products. For example, imagine a paint bucket or shampoo bottle in which every drop contains particles that are encoded with the product's manufacturing history - how it was made, in which factory, and when. "A bit like a fingerprint," says Grier, adding that the microscope can just as easily read a molecular message that has been imprinted on drugs, explosives or other goods. (Ben Fogelson)

9. Atom-sized building blocks

Generations of bright minds have been inspired by Lego bricks, the little plastic blocks that can be stuck together. These building blocks have become fantastic cars, elaborate castles and many other structures that are larger than the sum of their individual parts. Today, a whole generation of materials scientists are inspired by a new type of Lego: building blocks at the atomic level.

These new components consist of sheets of a material that can be as thin as a single layer of atoms. They can be stacked on top of each other in a fixed, neat order. This unprecedented fine-tuning can produce things with previously unknown electrical and optical properties. And it allows scientists to imagine devices made of materials that conduct electricity with very little resistance, faster and more powerful computers, clothing-like electronic applications that are extremely flexible, foldable and lightweight.

This breakthrough follows the development of graphene, that single lattice of carbon atoms that my colleagues and I isolated from a massive block of graphite in 2004 at the University of Manchester in England. We built this plate of repeating six-sided crystals - the atomic structure resembles a chain-link fence - by peeling off layers of one atom thick from the top of the block with tape. Over the past decade, researchers have found several dozen other crystal structures that can be pulled apart in this way - and their number is growing rapidly and steadily. Examples are mica and materials with exotic names like hexagonal boron nitride and molybdenum disulfide.

These crystal layers are considered two-dimensional, since a single atom represents the smallest possible layer thickness for any material; slightly denser crystals made up of three or more atoms can also be used. Its other dimensions, such as width and length, can be quite a bit larger, depending on the manufacturer's preferences. In recent years, the two-dimensional crystals have become a hot topic in materials science and solid state physics because of their many unique properties.

You can stack the layers in a pretty sturdy way. They do not connect to one another in the usual way, for example via covalent bonds to share electrons. But the atoms attract each other when they are in close proximity to one another, through a weak attraction called a van der Waals force. This pull is usually not strong enough to hold atoms and molecules together. However, since the two-dimensional layers are packed so tightly with atoms and so close together, the concentrated force is considerable.

To understand the tempting possibilities offered by this type of material technology, just think of room temperature superconductivity. The idea of ​​conducting electricity without loss of energy and without extremely cooling the lines for it was a goal of scientists for generations. If it is possible to find such conductive materials, it will advance our civilization. There is a consensus that this goal can be achieved in principle, but no one knows exactly how. Today, the highest temperature at which materials become superconducting is still incredibly cold - beyond minus 100 degrees Celsius. Little progress has been made over the past two decades.

We recently learned that some oxide superconductors can also be broken down into individual layers. What would happen if you put them back together in a different order and added additional crystal layers? We already know that superconductivity within oxides depends on a separation of the intermediate layer and that additional layers between the crystal planes can turn some weakly conductive and even insulating materials into superconductors.

The actual experiment to test this concept has not yet been conducted, mainly because the technology for making Lego materials at the atomic level is still in its infancy and because it is difficult to put complex, multilayered structures together. For the time being, these structures contain hardly more than five different layers and usually only use two or three different Lego building blocks: mostly graphene in combination with two-dimensional crystals made of non-conductive boron nitride and semiconducting materials such as molybdenum disulfide and tungsten diselenide. Since the newly created stacks consist of a large number of different materials, they are often called heterostructures. They are currently quite small, typically only ten square micrometers, less than the cross-section of a human hair.

Using these stacks, we can conduct experiments looking for novel electrical or optical properties and new applications. A fascinating aspect: as thin as these panels are, they are also completely flexible and transparent. This opens up possibilities for light-emitting devices that can be shaped in a wide variety of ways - for example into screens that can be folded or unfolded as soon as the user needs a larger format. Computer chips that lose less energy than current micro-components are also possible.

We assume that many of the structures we are looking for can be enlarged for industrial use, as has already been done with graphene and some other two-dimensional crystals. In the beginning, only tiny crystallites a few micrometers long were found, but today they can be produced in plates hundreds of square meters. There is still no magic cure to change the world. Nevertheless, our findings inspire. Advances in civilization have always followed closely on the heels of the discovery of new materials: from the Stone Age through the Bronze and Iron Ages to the era of silicon. Nanoscale Lego bricks embody something that has never existed before. The possibilities could be endless. (Andre K. Geim. The author is a physicist at the University of Manchester in England. In 2010 he was awarded part of the Nobel Prize in Physics for his work on graphs.)