Lifeboat Foundation

Chemical organization in reaction-diffusion systems offer a strategy to generate materials with ordered morphologies and architecture. Periodic structures can be formed using molecules or nanoparticles. An emerging frontier in materials science aims to combine nanoparticles and molecules. In a new report on Science Advances, Amanda J. Ackroyd and a team of scientists in chemistry, physics and nanomaterials in Canada, Hungary and the U.S. noted how solvent evaporation from a suspension of cellulose nanocrystals (CNCs) and L-(+)-tartaric acid [abbreviated L-(+)-TA] caused the phase separation of precipitation to result in the rhythmic alteration of CNC-rich, L-(+)-TA rings. The CNC-rich regions maintained a cholesteric structure, while the L-(+)-TA-rich bands formed via radially elongated bundles to expand the knowledge of self-organizing reaction-diffusion systems and offer a strategy to design self-organizing materials.

Chemical organization

The process of self-organization and self-assembly occurs universally in non-equilibrium systems of living matter, geochemical environments, materials science and in industry. Existing experiments that lead to periodic structures can be divided into two groups including the classical Liesegang-type experiments and chemical organization via periodic precipitation to generate materials with ordered morphologies and structural hierarchy. In this work, Ackroyd et al. developed a strategy for solvent evaporation to phase separate an aqueous solution of tartaric acid/cellulose nanocrystals [L-(+)-TA/CNC or TA/CNC] for its subsequent precipitation to result in a rhythmic alternation of CNC-rich or CNC-depleted ring-type regions. The team developed a kinetic model which agreed with the experimental results quantitatively. The work expands the range of self-organizing reaction-diffusion systems to pave the way for periodically structured functional materials.

Getting closer.

Drugs and vaccines circulate through the vascular system reacting according to their chemical and structural nature. In some cases, they are intended to diffuse. In other cases, like cancer treatments, the intended target is highly localized. The effectiveness of a medicine —and how much is needed and the side effects it causes —are a function of how well it can reach its target.

“A lot of medicines involve intravenous injections of drug carriers,” said Ying Li, an assistant professor of mechanical engineering at the University of Connecticut. “We want them to be able to circulate and find the right place at the right time and to release the right amount of drugs to safely protect us. If you make mistakes, there can be terrible side effects.”

Continue reading “Targeting tumors with nanoworms” »

Circa 2020 o.o!

Japanese researchers have had success with miniscule robots that are small enough to get inside and neutralize a cancer cell — and they want their creations to be ready to deal with future outbreaks of lethal viruses.

Multi-resistant pathogens are a serious and increasing problem in today’s medicine. Where antibiotics are ineffective, these bacteria can cause life-threatening infections. Researchers at Empa and ETH Zurich are currently developing nanoparticles that can be used to detect and kill multi-resistant pathogens that hide inside our body cells. The team published the study in the current issue of the journal Nanoscale (“Inorganic nanohybrids combat antibiotic-resistant bacteria hiding within human macrophages”).

Antibiotic-resistant bacteria are being swallowed by a human white blood cell. Colorized, scanning electron microscopic (SEM) image. (Image: CDC/NIAID)

In the arms race “mankind against bacteria”, bacteria are currently ahead of us. Our former miracle weapons, antibiotics, are failing more and more frequently when germs use tricky maneuvers to protect themselves from the effects of these drugs. Some species even retreat into the inside of human cells, where they remain “invisible” to the immune system. These particularly dreaded pathogens include multi-resistant staphylococci (MRSA), which can cause life-threatening diseases such as sepsis or pneumonia.

Scientists at Osaka University, in cooperation with Joanneum Research (Weiz, Austria), have developed wireless health monitoring patches that use embedded piezoelectric nanogenerators to power themselves with harvested biomechanical energy. This work may lead to new autonomous health sensors as well as battery-free wearable electronic devices.

As wearable technology and smart sensors become increasingly popular, the problem of providing power to all of these devices become more relevant. While the energy requirements of each component may be modest, the need for wires or even batteries become burdensome and inconvenient. That is why new energy harvesting methods are needed. Also, the ability for integrated health monitors to use ambient motion to both power and activate sensors will help accelerate their adoption in doctor’s offices.

Now, an international team of researchers from Japan and Austria has invented new ultraflexible patches with a ferroelectric polymer that can not only sense a patient’s pulse and blood pressure, but also power themselves from normal movements. The key was starting with a substrate just one micron thick. Using a strong electric field, ferroelectric crystalline domains in a copolymer were aligned so that the sample had a large electric dipole moment. Based on the piezoelectric effect, which is very efficient in converting natural motion into small electric voltages, the device responds rapidly to strain or pressure changes. These voltages can be transduced either into signals for the medical sensors or to directly harvest the energy. “Our e-health patches may be employed as part of screening for lifestyle-related diseases such as heart disorders, signs of stress, and sleep apnea,” first-author Andreas Petritz says.

Circa 2020

Nanotechnology development company UbiQD announced an optical fiber-coupled luminescent concentrator technology as a new tool for optimizing light in controlled environments, enabling light-guiding to future UbiGro spectrum-control greenhouse products.

EPFL scientists have developed AI-powered nanosensors that let researchers track various kinds of biological molecules without disturbing them.

The tiny world of biomolecules is rich in fascinating interactions between a plethora of different agents such as intricate nanomachines (proteins), shape-shifting vessels (lipid complexes), chains of vital information (DNA) and energy fuel (carbohydrates). Yet the ways in which biomolecules meet and interact to define the symphony of life is exceedingly complex.

Scientists at the Bionanophotonic Systems Laboratory in EPFL’s School of Engineering have now developed a new biosensor that can be used to observe all major biomolecule classes of the nanoworld without disturbing them. Their innovative technique uses nanotechnology, metasurfaces, infrared light and artificial intelligence. The team’s research has just been published in Advanced Materials.

Spin waves could unlock the next generation of computer technology, a new component allows physicists to control them.

Researchers at Aalto University have developed a new device for spintronics. The results have been published in the journal Nature Communications, and mark a step towards the goal of using spintronics to make computer chips and devices for data processing and communication technology that are small and powerful.

Traditional electronics uses electrical charge to carry out computations that power most of our day-to-day technology. However, engineers are unable to make electronics do calculations faster, as moving charge creates heat, and we’re at the limits of how small and fast chips can get before overheating. Because electronics can’t be made smaller, there are concerns that computers won’t be able to get more powerful and cheaper at the same rate they have been for the past 7 decades. This is where spintronics comes in.

There is no cheaper way to generate electricity today than with the sun. Power plants are currently under construction in sunny locations that will supply solar electricity for less than 2 cents per kilowatt hour. Solar cells available on the market based on crystalline silicon make this possible with efficiencies of up to 23 percent. Therefore they hold a global market share of around 95 percent. With even higher efficiencies of more than 26 percent, costs could fall further. An international working group led by photovoltaics researchers from Forschungszentrum Jülich now plan to reach this goal with a nanostructured, transparent material for the front of solar cells and a sophisticated design. The scientists report on their success of many years of research in the renowned scientific journal Nature Energy.

Silicon solar cells have been steadily improved over the past decades and have already reached a very high level of development. However, the disturbing effect of recombination still occurs after the absorption of sunlight and the photovoltaic generation of electrical charge carriers. In this process, negative and positive charge carriers that have already been generated combine and cancel each other out before they could be used for the flow of solar electricity. This effect can be countered by special materials that have a special property—passivation.

“Our nanostructured layers offer precisely this desired passivation,” says Malte Köhler, former Ph.D. student and first author from the Jülich Institute for Energy and Climate Research (IEK-5), who has since received his doctorate. In addition, the ultra-thin layers are transparent—so the incidence of light is hardly reduced—and exhibit high electrical conductivity.