Quantum leap

By Catherine
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Written by Catherine Bolgar

In the future, quantum computers will harness individual atoms or photons to do calculations that are currently impossible.

A quantum computer operates according to the very different rules of the quantum world, where, for example, atoms, photons (light particles) or subatomic particles can be two different things, or in two places, at the same time. So a computer made of atoms could do many computations simultaneously, explains Simon Benjamin, professor of quantum technologies at the University of Oxford, U.K.

In the future, quantum computers will harness individual atoms or photons to do calculations that are currently impossible.

In regular computers, a bit is a 0 or a 1. In quantum computers, a property called superposition means a bit—called a qubit—can be a 0, a 1 or both at once. “It sounds nonsense,” Prof. Benjamin acknowledges.

iStock_000000350047_SmallNevertheless, researchers are testing different kinds of qubits in different settings. Oxford University uses individual atoms of calcium in a vacuum, trapping them with electric fields so they don’t touch anything. “When the rest of the world touches a qubit, it makes it collapse and be either a 0 or a 1, and you’ve ruined it,” Prof. Benjamin says.

Oxford researchers use an ion trap which removes one electron from an atom, giving it an electrical charge, and making it easier to move. The ions are then shot with lasers, to create a ground state, an excited state, or a superposition (i.e. both states at once).

Controlling qubits is hard,” he says, but Oxford’s qubits are “arguably the best in the world, based on how they behave.”

Another approach is a superconducting quantum computer, which needs to be kept in a large refrigerator close to absolute zero. The computer consists of a little chip and superconductor. Electricity swirls around the superconducting ring, clockwise, counterclockwise or both at once. Researchers are seeking the best material for the superconducting ring, which may be aluminum, niobium or graphene.

A third approach, called a nitrogen-vacancy center, uses pink diamonds, whose color comes from a nitrogen atom where there’s a missing carbon atom. “You can put an extra unit of energy in that center,” Prof. Benjamin explains. It produces light, which will tell you whether you’re storing a 0 or 1 there.

“It’s a race among those approaches and some others,” he says. “In a few years’ time we’ll know who has won.”

Martin Laforest, senior manager, scientific outreach at the Institute for Quantum Computing, University of Waterloo, Canada, agrees it’s too soon to pick a winner. But he believes that superconducting qubits have momentum because they capitalize on nano-fabrication and microwave technology that have been developed over 50-60 years and push them to the extreme.

Although small computers with quantum properties exist, they aren’t yet faster than the best classical computers. In time, however, what might a quantum computer be able to do?

Like conventional computers in the 1940s, the first quantum computers could be powerful code-breakers. They could also be used for simulation, a potential game-changer in pharmaceuticals, clean energy and new materials.

Simulation could, for example, lead to better superconductors that transport solar energy collected in, say, the Sahara, to anywhere in the world. “Superconductors allow us to conduct electricity with zero loss,” Dr. Laforest says. “The problem is they work at minus 100 degrees Celsius and below. But imagine a superconductor that works at room temperature. We can’t do it now because we don’t fully understand how superconductors work. Our computers aren’t powerful enough to simulate how they work.”

Pharmaceutical design is mostly trial and error because “we don’t know exactly how a certain molecule of a drug interacts with the human body, or how the shape of a molecule interacts with other molecules, so we can fix any problems,” Dr. Laforest says.

Simulating molecular interactions is too complex for today’s computers, partly because molecules behave according to the rules of quantum mechanics. “But a quantum computer already works with quantum mechanics,” he says.

Similarly, quantum computers could be used to create new materials with new properties, such as strength, flexibility or conductivity. “These things would have a big impact on society,” Dr. Laforest says.

 

 

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.

Photos courtesy of iStock

Will dental visits soon be easier?

By Catherine
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Written by Catherine Bolgar

New devices and materials promise to make dentist visits more pleasant, and help maintain our teeth between checkups. Here’s how.

Devices: Dentists may soon be able to eliminate tooth cavities quickly and painlessly without any drilling or filling. Tooth-destroying plaque, which feeds on dissolved food, comprises a complex mixture of bacteria that release acids into teeth, slowly dissolving dental minerals. But researchers at Reminova Ltd., a King’s College London corporate spinoff, have developed a device that re-inserts the calcium and phosphate minerals.

“We can stop the process and we can reverse it,” says Christopher Longbottom, fellow at King’s College London and Reminova co-founder. It’s not straightforward, but he says, we “can speed up the process of remineralization.”

Two or three agents clean out the proteins and lipids that have seeped through the plaque and replaced the minerals, then a tiny, imperceptible current drives the good minerals back into the tooth. The process takes about one hour, which Reminova hopes to reduce to between 20 and 30 minutes.

An alternative method is for a graphene sensor 50 microns thick (i.e., half the width of a human hair) with gold electrodes acting as an antenna, to be printed onto water-soluble silk and “tattooed” onto the tooth. As Manu Sebastian Mannoor, assistant professor at the Stevens Institute of Technology in Hoboken, N.J., explains, the graphene, which conducts the bacteria’s electrical charge, is coated with peptides that bind to bacteria such as streptococcus mutans, listeria or salmonella.

A dentist could read the sensor like a radio frequency identification (RFID) tag to ascertain the extent of any decay or disease. The latter might include Heliobacter pylori, which is associated with stomach ulcers and cancer when found in saliva. Sensors could also be attached to bacteria-hosting objects such as hospital door handles or intravenous bags, warning of exposure to the likes of staphlylococcus.

Materials: For over 150 years, dentists have filled tooth cavities with mercury-based silver amalgam. More recently, researchers have sought alternatives, encouraged not least by the 2013 United Nations Minamata Convention on Mercury, which aims to reduce its harmful health and environmental effects.

One such possibility, for use as fillings and crowns, is glass ionomer cements. These enjoy numerous advantages: they don’t need an intermediary adhesive to bond to the tooth; like a tooth they expand and contract as temperatures change; they’re biocompatible; and they release fluoride. However, “the strength of these materials has not yet reached an optimal level,” says Ana Raquel Benetti, dentist and researcher at the Department of Odontology at the University of Copenhagen.

Dr. Benetti and Dr. Heloisa Bordallo studied the structure of conventional glass ionomer cements, with the aim of improving their durability. “Our work shows liquid mobility within the cements,” Dr. Benetti explains.

By improving the binding of the liquid to the cement structure, the material might become stronger.”

In other advances, scientists at the University of Rochester and University of Pennsylvania have found a way to use nanoparticles to deliver the antibacterial agent farnesol to plaque. Meanwhile, researchers at Anhui Medical University in Hefei, China, and the University of Hong Kong drew inspiration from the way mussels attach themselves to surfaces, and used a similar polydopamine to coat teeth, which helps remineralize their dentin, or interior.

And scientists at the Ninth People’s Hospital, Shanghai Key Laboratory, Shanghai Research Institute of Stomatology and Shanghai Jiao Ton University in China found that graphene oxide can fight bacteria in the mouth. Unlike treatments for tooth and gum-disease that rely on antibiotics (despite increasingly drug-resistant bacteria), graphene oxide destroys the bacteria’s cell walls and membranes, inhibiting their growth. One day, we might all protect our teeth with nanosheets.

 

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.

Photos courtesy of iStock

It’s a Wrap

By Catherine
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Written by Catherine Bolgar


Whether you like them or not, eggs, cheese, mushrooms or shrimp are likely to be part of your future shopping basket—as the raw materials in a new kind of plastic packaging.

New materials promise not only to reduce our reliance on petroleum products such as plastic, they also cut waste. Packaging accounted for more than 75 million tons (or 30%) of solid waste in the U.S. in 2013, while the European Union generates around 79 million tons of packaging waste annually.

However, waste from the agriculture industry is now being turned into biodegradable packaging materials. For example, Kirsi S. Mikkonen, a researcher at the University of Helsinki, is developing packaging films made from hemicelluloses, byproducts of the forestry industry and agriculture.

Cellulose, the part used by industry, makes up only 40% to 50% of wood, while hemicellulose and lignin each account for about 30%. Hemicelluloses can be retrieved from wood chips or, in thermo-mechanical mills, from wastewater.

Dr. Mikkonen converts the hemicelluloses into films that act as an effective barrier against oxygen. Edible films could protect food from drying out or spoiling, or even within food, to separate pizza crust from sauce. By coating paperboard with the films, she can make plastic-type containers.

Hemicelluloses and lignin can also be used in aerogels, which are porous and light but strong.

“When you put an aerogel in water, it acts like a sponge,” Dr. Mikkonen says. “It absorbs water and you can press it out, and it recovers its shape. We could make something like a soft pillow that could absorb moisture or drips from meat, or it could release active compounds and be used as active packaging.”

Innovations in active packaging abound. The Fraunhofer Research Institution for Modular Solid State Technologies in Munich has developed a sensor film that detects molecules called amines that are released when meat or fish starts to spoil. As amines build up, the sensors turn from yellow to blue, indicating the level of spoilage. Many companies now sell labels and films that keep fruits and vegetables fresh by absorbing ethlyene.

Egg whites could provide another form of active packaging. Alexander Jones, a researcher at the University of Georgia in Athens, Georgia, mixed the egg-white protein albumin with glycerol to create a plastic with antibacterial properties.

Albumin plastic could be used for food packaging, to decrease spoilage. It could also be mixed with conventional plastic to add antibacterial properties to medical products, says Suraj Sharma, associate professor at the University of Georgia’s College of Family and Consumer Sciences.

Another reason to mix in conventional plastic is that albumin plastic is too brittle to be used alone for, say, a catheter tube, which needs flexibility, Dr. Jones says.

He also tested plastics made from soy and whey proteins. Soy proteins had no antibacterial properties—“it actually fed bacteria,” he says. Whey proteins mixed with glycerol made antibacterial plastic, but whey plastic minus glycerol acted like soy-based plastic, promoting bacteria growth.

The protein-based plastics have other advantages. They compost quickly, and the manufacturing process uses lower temperatures than for petroleum-based plastics, thereby saving energy. Whey, a byproduct of cheese processing, requires treatment before disposal, so diverting it into plastics would be a boon.

For now, egg whites are far more expensive than polyethelyne. But Dr. Jones believes that we might tap waste streams to get cheaper raw materials.

Egg producers have eggs they don’t ship for various reasons,” Dr. Jones says. Using those “would reduce waste and also not compete with food as an end use.”

Shrimp shells are another waste source that can be turned into plastic. Harvard University researchers have turned chitin, a polysaccharide found in crustacean shells, into a strong, transparent material called shrilk, which can be used to make plastic bags, packaging and even diapers.

Meanwhile, Ecovative, a packaging company in Green Island, N.Y., uses mushrooms as the key ingredient in its compostable packaging. The root structure of a mushroom, called mycelium, acts like a glue. A mix of mycelium and agricultural byproducts is molded into different shapes, replacing styrofoam for example.

Packaging today is essential for society to function,” Dr. Mikkonen says. “We need packaging to deliver food from the maker to the retailer and then to the consumer. But it produces lots of waste. It’s really important to develop some biodegradable alternatives.”

 

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.

Photos courtesy of iStock



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