Lifeboat Foundation

Scientists in China and Sweden have determined that a pinch of capsaicin, the chemical compound that gives chili peppers their spicy sting, may be a secret ingredient for more stable and efficient perovskite solar cells. The research, published January 13 in the journal Joule, determined that sprinkling capsaicin into the precursor of methylammonium lead triiodide (MAPbI₃) perovskite during the manufacturing process led to a greater abundance of electrons (instead of empty placeholders) to conduct current at the semiconductor’s surface. The addition resulted in polycrystalline MAPbI3 solar cells with the most efficient charge transport to date.

“In the future, green and sustainable forest-based biomaterial additive technology will be a clear trend in non-toxic lead-free perovskite materials,” says Qinye Bao, a senior author of the study from East China Normal University. “We hope this will eventually yield a fully green perovskite solar cell for a clean energy source.”

While metal halide perovskite semiconductors represent a promising component for state-of-the-art solar cell technologies, they are plagued by nonradiative recombination, an undesirable electron-level process that reduces efficiency and exacerbates heat losses. Bao and colleagues sought out a natural, forest-based, inexpensive additive to overcome this limitation and enhance solar cell performance.

Researchers at Columbia Engineering report today that they have developed the first nanomaterial that demonstrates “photon avalanching,” a process that is unrivaled in its combination of extreme nonlinear optical behavior and efficiency. The realization of photon avalanching in nanoparticle form opens up a host of sought-after applications, from real-time super-resolution optical microscopy, precise temperature and environmental sensing, and infrared light detection, to optical analog-to-digital conversion and quantum sensing.

“Nobody has seen avalanching behavior like this in nanomaterials before,” said James Schuck, associate professor of mechanical engineering, who led the study published today by Nature. “We studied these new nanoparticles at the single-nanoparticle level, allowing us to prove that avalanching behavior can occur in nanomaterials. This exquisite sensitivity could be incredibly transformative. For instance, imagine if we could sense changes in our chemical surroundings, like variations in or the actual presence of molecular species. We might even be able to detect coronavirus and other diseases.”

Avalanching processes—where a cascade of events is triggered by series of small perturbations—are found in a wide range of phenomena beyond snow slides, including the popping of champagne bubbles, nuclear explosions, lasing, neuronal networking, and even financial crises. Avalanching is an extreme example of a nonlinear process, in which a change in input or excitation leads to a disproportionate—often disproportionately large—change in output signal. Large volumes of material are usually required for the efficient generation of nonlinear optical signals, and this had also been the case for photon avalanching, until now.

A keen sense of smell is a powerful ability shared by many organisms. However, it has proven difficult to replicate by artificial means. Researchers combined biological and engineered elements to create what is known as a biohybrid component. Their volatile organic compound sensor can effectively detect odors in gaseous form. They hope to refine the concept for use in medical diagnosis and the detection of hazardous materials.

Electronic devices such as cameras, microphones and pressure sensors enable machines to sense and quantify their environments optically, acoustically and physically. Our sense of smell however, despite being one of nature’s most primal senses, has proven very difficult to replicate artificially. Evolution has refined this sense over millions of years and researchers are working hard to catch up.

“Odors, airborne chemical signatures, can carry useful information about environments or samples under investigation. However, this information is not harnessed well due to a lack of sensors with sufficient sensitivity and selectivity,” said Professor Shoji Takeuchi from the Biohybrid Systems Laboratory at the University of Tokyo. “On the other hand, biological organisms use odor information extremely efficiently. So we decided to combine existing biological sensors directly with artificial systems to create highly sensitive volatile organic compound (VOC) sensors. We call these biohybrid sensors.”

In Michelle O’Malley’s lab, a simple approach suggests a big leap forward in addressing the challenge of antibiotic-resistant bacteria.

Scientists have long been aware of the dangerous overuse of antibiotics and the increasing number of antibiotic-resistant microbes that have resulted. While over-prescription of antibiotics for medicinal use has unsettling implications for human health, so too does the increasing presence of antibiotics in the natural environment. The latter may stem from the improper disposal of medicines, but also from the biotechnology field, which has depended on antibiotics as a selection device in the lab.

“In biotech, we have for a long time relied on antibiotic and chemical selections to kill cells that we don’t want to grow,” said UC Santa Barbara chemical engineer Michelle O’Malley. “If we have a genetically engineered cell and want to get only that cell to grow among a population of cells, we give it an antibiotic resistance gene. The introduction of an antibiotic will kill all the cells that are not genetically engineered and allow only the ones we want — the genetically modified organisms [GMOs] — to survive. However, many organisms have evolved the means to get around our antibiotics, and they are a growing problem in both the biotech world and in the natural environment. The issue of antibiotic resistance is a grand challenge of our time, one that is only growing in its importance.”

Would you like to capture a chemical transformation inside a cell live? Or maybe revolutionize microchips’ production by printing paths in a layer that has a thickness of just 100 nanometers? These and many other goals can now be achieved with the latest femtosecond laser created by a team of scientists led by Dr. Yuriy Stepanenko.

These days, there is a multitude of laser light sources. They each have their characteristics and different applications, such as observing stars, treating illnesses, and surface micro-machining. “Our goal is to develop new ones,” says Yuriy Stepanenko, head of the team of Ultrafast Laser Techniques at the Institute of Physical Chemistry of the Polish Academy of Sciences. “We deal with sources that produce ultrashort pulses of light. Really very, very short—femtosecond pulses (that’s a part of a second with 15 zeros after the decimal point). This is the scale on which, for example, intracellular chemical reactions take place. To see them, we have to ” take a photo” in this very short time. And thanks to the new laser, we can do just that.

We can also use our source for the very precise removal of materials from various surfaces without destroying them, says the scientist. We could, for example, clean the Mona Lisa using this method without damaging the layers of paint. We would only remove dust and dirt, a layer about 10 nanometers thick, explains Dr. Stepanenko, one of the authors of a study recently published in the Journal of Lightwave Technology.

Biotechnologists at Delft University of Technology have built an artificial chromosome in yeast. The chromosome can exist alongside natural yeast chromosomes, and serves as a platform to safely and easily add new functions to the micro-organism. Researchers can use the artificial chromosome to convert yeast cells into living factories capable of producing useful chemicals and even medicines.

Biotechnologists from all over the world are trying to engineer yeast cells and other micro-organisms such that they can produce useful substances. To do this, they have to make adjustments to the existing genetic material of the cell. For example, they insert a number of genes into the yeast genome using CRISPR-Cas9, or switch off existing genes, thereby gradually transforming yeast cells into ‘cell factories’ that produce useful substances.

The disadvantage of this method is that it is not possible to make all the necessary changes at once, but that several rounds of genetic manipulation are needed. This is time-consuming. Additionally, multiple sessions of DNA-tinkering using CRISPR-Cas9 can lead to mutations that disrupt (essential) functions. The result of this could be, for instance, that the metabolism of the cell is disrupted, causing problems with growth and division.

A team led by University of Minnesota Twin Cities researchers has discovered a groundbreaking one-step process for creating materials with unique properties, called metamaterials. Their results show the realistic possibility of designing similar self-assembled structures with the potential of creating “built-to-order” nanostructures for wide application in electronics and optical devices.

The research was published and featured on the cover of Nano Letters, a peer-reviewed scientific journal published by the American Chemical Society.

In general, metamaterials are materials made in the lab so as to provide specific physical, chemical, electrical, and optical properties otherwise impossible to find in naturally occurring materials. These materials can have unique properties which make them ideal for a variety of applications from optical filters and medical devices to aircraft soundproofing and infrastructure monitoring. Usually these nano-scale materials are painstakingly produced in a specialized clean room environment over days and weeks in a multi-step fabrication process.

Scientists have recently discovered a totally new type of chemical bond – and it’s way stronger than it has any right to be.

The new type of bond shows that the divide between powerful covalent bonds, which bind molecules together, and weak hydrogen bonds, which form between molecules and can be broken by something as simple as stirring salt into a glass of water, isn’t as clear as chemistry textbooks would suggest.

Think back to that high-school chemistry class, and you’ll remember that there are different types of bonds that link atoms together into molecules and crystal structures.

Reactive molecules, such as free radicals, can be produced in the body after exposure to certain environments or substances and go on to cause cell damage. Antioxidants can minimize this damage by interacting with the radicals before they affect cells.

Led by Enrique Gomez, professor of chemical engineering and materials science and engineering, Penn State researchers have applied this concept to prevent imaging damage to conducting polymers that comprise soft electronic devices, such as organic solar cells, organic transistors, bioelectronic devices and flexible electronics. The researchers published their findings in Nature Communications today (Jan. 8).

According to Gomez, visualizing the structures of conducting polymers is crucial to further develop these materials and enable commercialization of soft electronic devices—but the actual imaging can cause damage that limits what researchers can see and understand.