Materials – Lifeboat News: The Blog

Dec 15
2020

When less is more: A single layer of atoms boosts the nonlinear generation of light

In a new study an international research team led by the University of Vienna has shown that structures built around a single layer of graphene allow for strong optical nonlinearities that can convert light. The team achieved this by using nanometer-sized gold ribbons to squeeze light, in the form of plasmons, into atomically-thin graphene. The results, which are published in Nature Nanotechnology are promising for a new family of ultra-small tunable nonlinear devices.

In the last years, a concerted effort has been made to develop plasmonic devices to manipulate and transmit light through nanometer-sized devices. At the same time, it has been shown that nonlinear interactions can be greatly enhanced by using plasmons, which can arise when light interacts with electrons in a material. In a plasmon, light is bound to electrons on the surface of a conducting material, allowing plasmons to be much smaller than the light that originally created them. This can lead to extremely strong nonlinear interactions. However, plasmons are typically created on the surface of metals, which causes them to decay very quickly, limiting both the plasmon propagation length and nonlinear interactions. In this new work, the researchers show that the long lifetime of plasmons in graphene and the strong nonlinearity of this material can overcome these challenges.

In their experiment, the research team led by Philip Walther at the University of Vienna (Austria), in collaboration with researchers from the Barcelona Institute of Photonic Sciences (Spain), the University of Southern Denmark, the University of Montpellier, and the Massachusetts Institute of Technology (USA) used stacks of two-dimensional materials, called heterostructures, to build up a nonlinear plasmonic device. They took a single atomic layer of graphene and deposited an array of metallic nanoribbons onto it. The metal ribbons magnified the incoming light in the graphene layer, converting it into graphene plasmons. These plasmons were then trapped under the gold nanoribbons, and produced light of different colors through a process known as harmonic generation. The scientists studied the generated light, and showed that, the nonlinear interaction between the graphene plasmons was crucial to describe the harmonic generation.

Dec 14
2020

Stanford Designer is Making Bricks Out of Fast-Growing Mushrooms That Are Stronger than Concrete

Mushroom buildings! 😃

Using mycelium, Bay-area designer Phil Ross creates an 6X6 arch out of mushroom roots turned into bricks, and he wants to build a house next.

Dec 14
2020

Mass of human-made materials now equals the planet’s biomass

We are doubling the mass of the human-made, ‘anthropogenic’ part of the world every 20 years. The entire planet Earth could be converted to human uses within the next several centuries if this trend continues.

Dec 13
2020

3D vortex rings appear in a bulk magnet

Researchers have observed three-dimensional magnetic vortex rings in a real-world magnetic material for the first time. Contrary to theoretical predictions, these rings – which are spin configurations within the material’s bulk – are remarkably stable and could move through the material like smoke rings move through air. If such movement can be controlled, they might have applications in energy-efficient 3D data storage and processing.

In a ferromagnetic material, the spatial distribution of the local magnetization is responsible for the material’s magnetic properties. These spatial distributions can be very complex, and intricate magnetic “textures” are behind many modern technologies, including hard disk drives. A vortex is one such distribution, and it forms when the material’s magnetization circulates around a central core.

Vortex rings are more sophisticated still, and occur naturally in physical systems such as fluids, plasmas and turbulent gases in the Earth’s atmosphere. However, while they have long been predicted to exist in ferromagnets, they have never been observed there until now.

Dec 13
2020

Phase Changing Material Smart Curtains Keep Room At 25°C

It seems even curtains are getting an upgrade. 😃

These intelligent curtains are printed with a material called PCM (Phase Changing Material) that absorbs heat and releases it when needed.

Dec 12
2020

Graphene is being used to surface a road in Oxfordshire

Potholes may soon reach the end of the road, as an Oxfordshire village hosts the first UK trial of a graphene-based wonder material designed to prevent cracks forming.

Graphene is a super-strong material made of specially-structured carbon.

Work will begin today on laying a 820 yard (750 metre) –long stretch of the wonder material on the main road through Curbridge, west of Oxford.

Dec 12
2020

New metamaterial enhances natural cooling without power input

Thin glass-polymer sheet increases passive radiative cooling.

A new metamaterial film provides cooling without needing a power input. Made out of glass microspher.

Dec 12
2020

Thermal Metamaterials Make it Possible to Control the Flow of Heat at Will

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Dec 10
2020

Human-made materials may now outweigh all living things on Earth, report finds

It’s the two highly problematic trends, that the study relates here, that are important: The comparatively slow, but long-term, continuous human-induced reduction of the global biomass stock vis-à-vis the exponentially growing anthropogenic (human-made) mass,” Krausmann said by email. “Better knowledge about the dynamics and patterns of anthropogenic mass, and how it is linked to service provision and resource flows is key for sustainable development. The big question is how much anthropogenic mass do we need for a good life.

The year 2020 could be the year when human-made mass surpasses the overall weight of biomass — estimated to be roughly 1,100,000,000,000 tons, or 1.1 teratons — a milestone scientists say speaks to the enormous impact that humans have had on the planet.

The analysis was published Wednesday in the scientific journal Nature, and was conducted by a group of researchers from Israel’s Weizmann Institute of Science.

Dec 10
2020

The Real Spider Man — Alex Greenhalgh, CEO, Spintex — Novel And Powerful Bio-Materials and Fabrics

Spider silk is a protein fiber spun by spiders, which they use to make webs or other structures, which function as sticky nets to catch other animals, or as nests or cocoons to protect their offspring, or to wrap up prey. They can also use their silk to suspend themselves, to float through the air, or to glide away from predators.

Each spider and each type of silk has a set of mechanical properties optimized for their biological function, but in particular, their dragline silks, have exceptional mechanical properties. They exhibit a unique combination of high tensile strength and extensibility which enables a silk fiber to absorb a large amount of energy before breaking with this estimated tensile strength several times that of steel.

Alex Greenhalgh, is the CEO, Spintex, a spin-out from the University of Oxford, pushing the boundaries of bio-inspired spinning and silk materials to provide much needed solution in sustainable and technical textiles.

Alex is a biologist and programmer with a working background in microbiology, clinical trials with a focus on GCP compliance, and silk and protein science where he has been a research assistant in the Oxford Silk Group for the last three-years. His research experience includes characterization of liquid silks and fibres with techniques such as rheology, fluorimetry, calorimetry, electrophoresis and tensile testing.