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Category: nanotechnology – Page 177

Topological insulators have notable manifestations of electronic properties. The helicity-dependent photocurrents in such devices are underpinned by spin momentum-locking of surface Dirac electrons that are weak and easily overshadowed by bulk contributions. In a new report now published on Science Advances, X. Sun and a research team in photonic technologies, physics and photonic metamaterials in Singapore and the U.K. showed how the chiral response of materials could be enhanced via nanostructuring. The tight confinement of electromagnetic fields in the resonant nanostructures enhanced the photoexcitation of spin-polarized surface states of a topological insulator to allow an 11-fold increase of the circular photogalvanic effect and a previously unobserved photocurrent dichroism at room temperature. Using this method, Sun et al. controlled the spin transport in topological materials via structural design, a hitherto unrecognized ability of metamaterials. The work bridges the gap between nanophotonics and spin electronics to provide opportunities to develop polarization-sensitive photodetectors.

Chirality

Chirality is a ubiquitous and fascinating natural phenomenon in nature, describing the difference of an object from its mirror image. The process manifests in a variety of scales and forms from galaxies to nanotubes and from organic molecules to inorganic compounds. Chirality can be detected at the atomic and molecular level in fundamental sciences, including chemistry, biology and crystallography, as well as in practice, such as in the food and pharmaceutical industry. To detect chirality, scientists can use interactions with electromagnetic fields, although the process can be hindered by a large mismatch between the wavelength of light and the size of most molecules at nanoscale dimensions. Designer metamaterials with structural features comparable to the wavelength of light can provide an independent approach to devise optical properties on demand to enhance the light-matter interaction to create and enhance the optical chirality of metamaterials. In this work, Sun et al.

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The ‘engine’ is actually a nanotube, powered by an enzyme-triggered biocatalytic reaction using urea as fuel. The reaction creates an internal flow that extends out into the fluid, causing an open cavity to form. This results in thrust, propelling the nanotube along.

Samuel Sánchez was one of the lead researchers from the previous record holders where their nanotube jet engine measured 600nm across and weighed 1 femtogram (10^−15 kg).

Xing Ma and Samuel Sánchez recognise both Ana C. Hortelao (Spain) and Albert Miguel-López (Spain) contribution to the research as well as the support from their affiliated institutions:

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Glass, rubber and plastics all belong to a class of matter called amorphous solids. And in spite of how common they are in our everyday lives, amorphous solids have long posed a challenge to scientists.

Since the 1910s, scientists have been able to map in 3D the atomic structures of crystals, the other major class of solids, which has led to myriad advances in physics, chemistry, biology, , geology, nanoscience, drug discovery and more. But because aren’t assembled in rigid, repetitive atomic structures like crystals are, they have defied researchers’ ability to determine their with the same level of precision.

Until now, that is.

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Would you use one in your phone though?

A U.S. startup combined radioactive isotopes from nuclear waste with ultra-slim layers of nanodiamonds to assemble a ridiculous battery that allegedly can last 28000 years.

According to the California startup in question, called NDB (Nano Diamond Battery), their product is a “high-power diamond-based alpha, beta, and neutron voltaic battery.”

The energy comes from waste graphite that was previously used in graphite-cooled nuclear reactors. The radioactive graphite is encased in layers of nano-thin, single crystalline diamond, which act both as a semiconductor and heat sink.

Continue reading “Diamond battery powered by nuclear waste runs for 28,000 years” | >

The genome editing technology CRISPR has emerged as a powerful new tool that can change the way we treat disease. The challenge when altering the genetics of our cells, however, is how to do it safely, effectively, and specifically targeted to the gene, tissue and organ that needs treatment. Scientists at Tufts University and the Broad Institute of Harvard and MIT have developed unique nanoparticles comprised of lipids—fat molecules—that can package and deliver gene editing machinery specifically to the liver. In a study published today in the Proceedings of the National Academy of Sciences, they have shown that they can use the lipid nanoparticles (LNPs) to efficiently deliver the CRISPR machinery into the liver of mice, resulting in specific genome editing and the reduction of blood cholesterol levels by as much as 57%—a reduction that can last for at least several months with just one shot.

The problem of high cholesterol plagues more than 29 million Americans, according to the Centers for Disease Control and Prevention. The condition is complex and can originate from multiple as well as nutritional and lifestyle choices, so it is not easy to treat. The Tufts and Broad researchers, however, have modified one gene that could provide a protective effect against elevated cholesterol if it can be shut down by gene editing.

The gene that the researchers focused on codes for the angiopoietin-like 3 enzyme (Angptl3). That enzyme tamps down the activity of other enzymes—lipases—that help break down cholesterol. If researchers can knock out the Angptl3 gene, they can let the lipases do their work and reduce levels of cholesterol in the blood. It turns out that some lucky people have a natural mutation in their Angptl3 gene, leading to consistently low levels of triglycerides and low-density lipoprotein (LDL) cholesterol, commonly called “bad” cholesterol, in their bloodstream without any known clinical downsides.

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Roundworms don’t have eyes or the light-absorbing molecules required to see. Yet, new research shows they can somehow sense color. The study, published in the journal Science, suggests worms use this ability to assess the risk of feasting on potentially dangerous bacteria that secrete blue toxins. The researchers pinpointed two genes that contribute to this spectral sensitivity and are conserved across many organisms, including humans.

“It’s amazing to me that a —with neither eyes nor the molecular machinery used by eyes to detect colors—can identify and avoid a toxic bacterium based, in part, on its ,” says H. Robert Horvitz, the David H. Koch Professor of Biology at MIT, a member of the McGovern Institute for Brain Research and the Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute Investigator, and the co-senior author of the study. “One of the joys of being a biologist is the opportunity to discover things about nature that no one has ever imagined before.”

The roundworm in question, Caenorhabditis elegans, is only about a millimeter long. Despite their minute stature and simple nervous system, these nematodes display a complex repertoire of behaviors. They can smell, taste, sense touch, react to temperature, and even escape or change their feeding patterns in response to bright, . Although researchers once thought that these bury themselves deep in soil, it’s becoming increasingly clear that C. elegans prefers compost heaps above ground that offer some sun exposure. As a result, roundworms may have a need for light-and color-sensing capabilities after all.

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A new type of 3D-printed battery which uses electrodes made from vegetable starch and carbon nanotubes could provide mobile devices with a more environmentally-friendly, higher-capacity source of power.

A team of engineers led from the University of Glasgow have developed the battery in a bid to make more sustainable batteries capable of storing and delivering power more efficiently. The battery’s design and fabrication is outlined in a paper published in the Journal of Power Sources.

Lithium-ion batteries provide a useful combination of lightweight, compact form factors and the ability to withstand many cycles of charging and discharging. That has made them ideally suited for use in a wide array of devices, including laptops, mobile phones, smart watches, and electric vehicles.

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Using a new class of nanoparticles that are two thousand times thinner than a human hair, Sakhrat Khizroev, a professor of electrical and computer engineering at the University’s College of Engineering, hopes to unlock the secrets of the brain.

The neurosurgeon who examined Sakhrat Khizroev after he lost his eyesight in a horrible accident told the young scientist that his vision would come back slowly. Then, after months of living in darkness, it finally started to return.

At first, the images were blurry and fragmented, as if someone were looking through a narrow window and seeing only part of a picture. But with each passing day, everything Khizroev looked at appeared clearer, sharper.

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The lives of infomorphs (or ‘cyberhumans’) who have no permanent bodies but possess near-perfect information-handling abilities, will be dramatically different from ours. Infomorphs will achieve the ultimate morphological freedom. Any infomorph will be able to have multiple cybernetic bodies which can be assembled and dissembled at will by nanobots in the physical world if deemed necessary, otherwise most time will be spent in the multitude of virtual bodies in virtual enviro… See More.

“I am not a thing — a noun. I seem to be a verb, an evolutionary process — an integral function of the Universe.” — Buckminster Fuller

The term ‘Infomorph’ was first introduced in “The Silicon Man” by Charles Platt in 1991 and later popularized by Alexander Chislenko in his paper “Networking in the Mind Age”: “The growing reliance of system connections on functional, rather than physical, proximity of their elements will dramatically transform the notions of personhood and identity and create a new community of distributed ‘infomorphs’ — advanced informational entities — that will bring the ongoing process of liberation of functional structures from material dependence to its logical conclusions. The infomorph society will be built on new organizational principles and will represent a blend of a superliquid economy, cyberspace anarchy and advanced consciousness.”

The new post-Singularity system will inherit many of today’s structures but at the same time will develop new traits beyond our current human comprehension. The ability of future machines and posthumans alike to instantly transfer knowledge and directly share experiences with each other will lead to evolution of intelligence from the hive ontology of individual biological minds to the global hyperconnected society of digital minds.

Continue reading “First Look Over the Event Horizon of Singularity: Your Future Life as a Cyberhuman” | >

A new class of quantum dots deliver a stable stream of single, spectrally tunable infrared photons under ambient conditions and at room temperature, unlike other single photon emitters. This breakthrough opens a range of practical applications, including quantum communication, quantum metrology, medical imaging and diagnostics, and clandestine labeling.

“The demonstration of high single-photon purity in the infrared has immediate utility in areas such as quantum key distribution for secure communication,” said Victor Klimov, lead author of a paper published today in Nature Nanotechnology by Los Alamos National Laboratory scientists.

The Los Alamos team has developed an elegant approach to synthesizing the colloidal-nanoparticle structures derived from their prior work on visible light emitters based on a core of cadmium selenide encased in a cadmium sulfide shell. By inserting a mercury sulfide interlayer at the core/shell interface, the team turned the into highly efficient emitters of that can be tuned to a specific wavelength.

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