Energy flow in semiconductors: new insights thanks to ultrafast spectroscopy

It took three years for researchers Grazia Raciti, Begoña Abad Mayor, and Ilaria Zardo (from left to right) to develop and characterize the complex setup – only then were the now-published measurements possible.
Photo Credit: C. Möller, Swiss Nanoscience Institute, University of Basel

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Researchers achieved unprecedented accuracy in observing energy flow mechanisms within the semiconductor germanium, detailing step-by-step energy transfer from the electronic system to the atomic lattice following ultrafast excitation.
• Methodology: The team utilized a novel combination of time-resolved Raman spectroscopy to measure lattice vibration changes and transient reflection spectroscopy to record light behavior, stimulating the material with 30-femtosecond laser pulses and validating results with computer simulations.
• Key Data: The experimental setup detected intensity changes of less than 1 percent and frequency shifts under 0.2 cm⁻¹ with a temporal resolution capable of distinguishing picosecond-scale responses from microsecond-interval pulses.
• Significance: This study provides a comprehensive understanding of how energy dissipates and converts to heat in semiconductors, addressing critical challenges regarding overheating and efficiency in modern electronics.
• Future Application: Findings will directly inform the design of next-generation computer chips, sensors, and phononic components that offer faster recovery times and reduced thermal accumulation.
• Branch of Science: Condensed Matter Physics and Nanoscience.
• Additional Detail: The specific combination of spectroscopic methods allowed for the simultaneous observation of frequency, intensity, and duration of lattice vibrations (phonons) as they evolved over time.

Purdue mRNA therapy delivery system proves to be shelf-stable, storable

The Proceedings of the National Academy of Sciences has published research about a Purdue University virus-mimicking platform technology that targets bladder cancer cells with mRNA therapies. The LENN platform scientists include, from left, Christina Ferreira, Saloni Darji, Bennett Elzey, Joydeep Rakshit, Feng Qu and David Thompson.
Photo Credit: Purdue University /Ali Harmeson

Scientific Frontline: "At a Glance" Summary

• Main Discovery: The LENN (Layer-by-layer Elastin-like Polypeptide Nucleic Acid Nanoparticle) platform successfully delivers mRNA therapies to bladder cancer cells while retaining full biological activity after being freeze-dried into a shelf-stable powder.
• Methodology: Researchers engineered a virus-mimicking dual-layer nanoparticle to condense and protect nucleic acids, then subjected the formulation to lyophilization (freeze-drying) and storage at -20°C to validate its stability and rehydration properties.
• Key Data: The lyophilized samples maintained complete structural integrity and functionality after three days of storage, successfully targeting upregulated receptors on tumor cells without triggering an immune response.
• Significance: This technology overcomes the severe cold-chain limitations of current lipid nanoparticle systems—which often require storage below -45°C—by providing a biomanufacturable, storable powder form that facilitates easier global distribution.
• Future Application: The team is upscaling the system for preclinical evaluation and initiating efficacy and safety studies in mouse models of bladder cancer.
• Branch of Science: Nanomedicine, Pharmaceutical Chemistry, and Oncology.
• Additional Detail: Multiple reaction monitoring (MRM) profiling confirmed that the system utilizes natural entry pathways and avoids immune detection, potentially solving the "redosing" clearance issues associated with traditional viral vectors.

A Nanomaterial Flex — MXene Electrodes Help OLED Display Technology Shine, While Bending and Stretching

Researchers from Drexel University and Seoul National University have created organic light-emitting diodes (OLEDs) that could improve mobile technology displays and enable wearable technology.
Photo Credit: Courtesy of Drexel University

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Researchers successfully engineered a highly stretchable Organic Light-Emitting Diode (OLED) capable of expanding to 1.6 times its original length (60% elongation) while maintaining functional electroluminescence, overcoming the rigidity of traditional displays.
• Electrode Mechanism: The device replaces brittle indium tin oxide (ITO) components with transparent, flexible electrodes composed of MXene nanomaterials and silver nanowires, which provide high electrical conductivity and mechanical robustness under stress.
• Active Layer Innovation: A specialized "exciplex-assisted phosphorescent" (ExciPh) organic layer was developed to serve as the light-emitting medium, utilizing chemical engineering to facilitate efficient charge transport and exciton formation even during physical deformation.
• Performance Metrics: The OLEDs demonstrate superior stability compared to existing technologies, exhibiting only a 10.6% reduction in performance when subjected to significant strain and retaining 83% of light output after 100 repeated stretching cycles.
• Significance/Application: This technology clears the path for "skin-mounted" displays and deformable optoelectronics, enabling wearable devices that can visualize real-time health data (such as body temperature and blood flow) directly on the skin.

X-raying auditory ossicles – a new technique reveals structures in record time

Scientists at PSI were able to observe the local collagen structures in an ossicle by scanning it with an X-ray beam. The different colours of the cylinders indicate how strongly the collagen bundles are spatially aligned in a section measuring 20 by 20 by 20 micrometres.
Image Credit: © Paul Scherrer Institute PSI/Christian Appel

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Researchers refined a "tensor tomography" X-ray diffraction technique that simultaneously detects biological structures ranging from nanometers to millimeters, significantly accelerating the imaging process.
• Methodology: The team used a precisely rotated X-ray beam (approx. 20 micrometers wide) to generate millions of interference patterns around two axes, which software then reconstructed into a 3D tomogram.
• Key Statistic: The optimized process reduced the measurement time for a complete tomogram from roughly 24 hours to just over one hour.
• Context: To validate the method, the team imaged the auditory ossicle (anvil) of the ear, successfully mapping the spatial orientation of nanometer-sized collagen fibers crucial for sound transmission.
• Significance: This drastic reduction in scan time makes statistical studies involving hundreds of samples feasible, aiding biomedical research in areas like bone tissue analysis and implant development.

Nanotechnology: In-Depth Description

Scientific Frontline / AI generated

Nanotechnology is the branch of science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometers. It involves the manipulation and control of matter on an atomic, molecular, and supramolecular scale to create materials, devices, and systems with fundamentally new properties and functions.

Surfing on the waves of the microcosm

A particle (red sphere) is guided from left to its destination (right) using a laser trap (double-cone) by means of a protocol developed in the study, which is described by the parameter λ. A known time-dependent external force field F (t) acts on this environment. The optimised protocol exploits this force field in a way that extracts the maximum amount of work. This can be applied to various external fields, to active particles and to micro-robot transport problems. 
Image Credit: HHU/Kristian S. Olsen

Conditions can get rough in the micro- and nanoworld. To ensure that e.g. nutrients can still be optimally transported within cells, the minuscule transporters involved need to respond to the fluctuating environment. Physicists at Heinrich Heine University Düsseldorf (HHU) and Tel Aviv University in Israel have used model calculations to examine how this can succeed. They have now published their results – which could also be relevant for future microscopic machines – in the scientific journal Nature Communications. 

When planning an ocean crossing, sailors seek a course, which makes optimum use of favorable wind and ocean currents, and maneuver to save time and energy. They also react to random fluctuations in wind and currents and take advantage of fair winds and waves. Such considerations regarding energy costs are also important for transport processes at the micro- and nanoscale. For example, molecular motors should use as little energy as possible when transporting nutrients from A to B between and within biological cells.  

Nasal drops fight brain tumors noninvasively

Researchers at WashU Medicine have developed a noninvasive medicine delivered through the nose that successfully eliminated deadly brain tumors in mice. The medicine is based on a spherical nucleic acid, a nanomaterial (labeled red) that travels along a nerve (green) from the nose to the brain, where it triggers an immune response to eliminate the tumor.
Image Credit: Courtesy of Alexander Stegh

Researchers at Washington University School of Medicine in St. Louis, along with collaborators at Northwestern University, have developed a noninvasive approach to treat one of the most aggressive and deadly brain cancers. Their technology uses precisely engineered structures assembled from nano-size materials to deliver potent tumor-fighting medicine to the brain through nasal drops. The novel delivery method is less invasive than similar treatments in development and was shown in mice to effectively treat glioblastoma by boosting the brain’s immune response.

Glioblastoma tumors form from brain cells called astrocytes and are the most common kind of brain cancer, affecting roughly three in 100,000 people in the U.S. Glioblastoma generally progresses very quickly and is almost always fatal. There are no curative treatments for the disease, in part because delivering medicines to the brain remains extremely challenging.

Rice engineers show lab grown diamond films can stop costly mineral buildup in pipes

Pulickel Ajayan and Xiang Zhang
Photo Credit: Jeff Fitlow/Rice University

In industrial pipes, mineral deposits build up the way limescale collects inside a kettle ⎯ only on a far larger and more expensive scale. Mineral scaling is a major issue in water and energy systems, where it slows flow, strains equipment and drives up costs.

A new study by Rice University engineers shows that lab-grown diamond coatings could resolve the issue, providing an alternative to chemical additives and mechanical cleaning, both of which offer only temporary relief and carry environmental or operational downsides.

“Because of these limitations, there is growing interest in materials that can naturally resist scale formation without constant intervention,” said Xiang Zhang, assistant research professor of materials science and nanoengineering and a first author on the study alongside Rice postdoctoral researcher Yifan Zhu. “Our work addresses this urgent need by identifying a coating material that can ‘stay clean’ on its own.”

Innovation turns building vents into carbon-capture devices

A carbon nanofiber-based direct air capture filter developed by the University of Chicago Pritzker School of Molecular Engineering could turn existing building ventilation systems into carbon-capture devices while cutting homeowners’ energy costs. Through life cycle assessment, the air filter shows a carbon removal efficiency of 92.1% from cradle to grave.
Photo Credit: Elaina Eichorn

With a newly developed nanofiber filter, air conditioners, heaters and other HVAC systems could remove airborne carbon dioxide while cutting energy costs

A nanofiber air filter developed at the University of Chicago could turn existing building ventilation into carbon-capture devices while cutting homeowners’ energy costs.

In a paper recently published in Science Advances, researchers from the lab of Asst. Prof. Po-Chun Hsu in the Pritzker School of Molecular Engineering (UChicago PME) developed a distributed carbon nanofiber direct air capture filter that could potentially turn every home, office, school or other building into a small system working toward the global problem of airborne carbon dioxide.

A life-cycle analysis shows that—even after factoring this extra CO2 released by everything from manufacture and transportation to maintenance and disposal—the new filter is more than 92% efficient in removing the gas from the air.

A system for targeted drug delivery using magnetic microrobots

Microrobots can be transported and activated in a safe and controlled manner, marking a decisive step forward in the use of these technological devices in targeted medical treatments.
Photo Credit: Courtesy of University of Barcelona

The study, led by the Swiss Federal Institute of Technology Zurich (ETH Zurich) and published in the journal Science, involves Professor Josep Puigmartí-Luis from the Faculty of Chemistry and the Institute of Theoretical and Computational Chemistry (IQTC) of the University of Barcelona. He is the only researcher from a Spanish institution to sign this paper, which is the result of the European ANGIE project, an initiative coordinated by Professor Salvador Pané (ETH) in collaboration with the Chemistry In Flow and Nanomaterials Synthesis (ChemInFlow) research group, led by Professor Puigmartí. 

The new microrobotic platform presents an innovative strategy for administering drugs in a precise and targeted manner. It is scalable and can be applied to numerous situations in which the administration of therapeutic agents is difficult to access, such as tumors, arteriovenous malformations, localized infections, or tissue injuries. 

Nanorobots transform stem cells into bone cells

Prof. Berna Özkale Edelmann, together with researchers at her Microrobotic Bioengineering Lab at the Technical University of Munich (TUM), developed a system in which stem cells can be transformed into bone cells through mechanical stimulation.
Photo Credit: Astrid Eckert / Technische Universität München

For the first time, researchers at the Technical University of Munich (TUM) have succeeded in using nanorobots to stimulate stem cells with such precision that they are reliably transformed into bone cells. To achieve this, the robots exert external pressure on specific points in the cell wall. The new method offers opportunities for faster treatments in the future.

Prof. Berna Özkale Edelmann’s nanorobots consist of tiny gold rods and plastic chains. Several million of them are contained in a gel cushion measuring just 60 micrometers, together with a few human stem cells. Powered and controlled by laser light, the robots, which look like tiny balls, mechanically stimulate the cells by exerting pressure. “We heat the gel locally and use our system to precisely determine the forces with which the nanorobots press on the cell – thereby stimulating it,” explains the professor of nano- and microrobotics at TUM. This mechanical stimulation triggers biochemical processes in the cell. Ion channels change their properties, and proteins are activated, including one that is particularly important for bone formation.

New nanomedicine wipes out leukemia in animal study

The real-time cellular uptake of spherical nucleic acids (SNAs) and fusion with leukemia cells’ lysosomes, where the SNAs degrade and release potent chemotherapeutics. SNAs are shown in red; cells’ cytoskeletons are green; and cells’ nuclei are blue.
Video Credit: Chad A. Mirkin Research Group

In a promising advance for cancer treatment, Northwestern University scientists have re-engineered the molecular structure of a common chemotherapy drug, making it dramatically more soluble and effective and less toxic.

In the new study, the team designed a new drug from the ground up as a spherical nucleic acid (SNA) — a nanostructure that weaves the drug directly into DNA strands coating tiny spheres. This design converts a poorly soluble, weakly performing drug into a powerful, targeted cancer killer that leaves healthy cells unharmed.

Nanopore signals, machine learning unlocks new molecular analysis tool

Illustration of voltage-matrix nanopore profiling. The artistic rendering depicts proteins (colored shapes) being analyzed by solid-state nanopores under varying voltage conditions. By combining nanopore signals with machine learning, researchers can discriminate protein mixtures and detect changes in molecular populations.
Image Credit: ©2025 Sotaro Uemura, The University of Tokyo

Understanding molecular diversity is fundamental to biomedical research and diagnostics, but existing analytical tools struggle to distinguish subtle variations in the structure or composition among biomolecules, such as proteins. Researchers at the University of Tokyo have developed a new analytical approach, which helps overcome this problem. The new method, called voltage-matrix nanopore profiling, combines multivoltage solid-state nanopore recordings with machine learning for accurate classification of proteins in complex mixtures, based on the proteins’ intrinsic electrical signatures.

The study, published in Chemical Science, demonstrates how this new framework can identify and classify “molecular individuality” without the need for labels or modifications. The research holds promise of providing a foundation that could lead to more advanced and wider applications of molecular analysis in various areas, including disease diagnosis.

DNA nanospring measures cellular motor power

Experimental design for the force measurement of KIF1A.
An inert protein known as KIF5B serves as the anchor from which KIF1A pulls the nanospring. As with more familiar springs, the extended length correlates with the force being applied. But in this case, the DNA nanospring is also labeled with fluorescent molecules which give away how far it stretches to make visualization of KIF1A’s motile strength possible.
Image Credit: ©2025 Hayashi et al
(CC BY-ND 4.0)

Cells all require the transport of materials to maintain their function. In nerve cells, a tiny motor made of protein called KIF1A is responsible for that. Mutations in this protein can lead to neurological disorders, including difficulties in walking, intellectual impairment and nerve degradation. It’s known that mutations in KIF1A also result in a weakened motor performance, but this has been difficult to measure so far. Researchers including those from the University of Tokyo and the National Institute of Information and Communications Technology (NICT) in Japan have measured changes in the force of KIF1A using a nanospring, a tiny, coiled structure, made of DNA which could lead to improved diagnosis of diseases related to the protein’s mutations.

Scientists uncover room-temperature route to improved light-harvesting and emission devices

Dasom Kim
Photo Credit: Jorge Vidal/Rice University

Atoms in crystalline solids sometimes vibrate in unison, giving rise to emergent phenomena known as phonons. Because these collective vibrations set the pace for how heat and energy move through materials, they play a central role in devices that capture or emit light, like solar cells and LEDs.

A team of researchers from Rice University and collaborators have found a way to make two different phonons in thin films of lead halide perovskite interact with light so strongly that they merge into entirely new hybrid states of matter. The finding, reported in a study published in Nature Communications, could provide a powerful new lever for controlling how perovskite materials harvest and transport energy.

To get a specific light frequency in the terahertz range to interact with phonons in the halide perovskite crystals, the researchers fabricated nanoscale slots ⎯ each about a thousand times thinner than a sheet of cling wrap ⎯ into a thin layer of gold. The slots acted like tiny metallic traps for light, tuning its frequency to that of the phonons and thus giving rise to a strong form of interaction known as “ultrastrong coupling.”

Supercharging vinegar’s wound healing power

Image Credit: Courtesy of Flinders University

A new study suggests adding microscopic particles to vinegar can make them more effective against dangerous bacterial infections, with hopes the combination could help combat antibiotic resistance.

The research, led by researchers at QIMR Berghofer, Flinders University and the University of Bergen in Norway, has resulted in the ability to boost the natural bacterial killing qualities of vinegar by adding antimicrobial nanoparticles made from carbon and cobalt.

Wounds that do not heal are often caused by bacterial infections and are particularly dangerous for the elderly and people with diabetes, cancer and other conditions.

Acetic acid (more commonly known as vinegar) has been used for centuries as a disinfectant, but it is only effective against a small number of bacteria, and it does not kill the most dangerous types.

The findings have been published in the international journal ACS Nano.

Scientists visualize atomic structures in moiré materials

On the left is an artistic depiction of a twisted double layer forming a moiré pattern created by overlapping 2D sheets; each layer’s structure is shown separately on the right.
Image Credit: Sumner Harris/ORNL, U.S. Dept. of Energy

Researchers with the Department of Energy’s Oak Ridge National Laboratory and the University of Tennessee, Knoxville, have created an innovative method to visualize and analyze atomic structures within specially designed, ultrathin bilayer 2D materials. When precisely aligned at an angle, these materials exhibit unique properties that could lead to advancements in quantum computing, superconductors and ultraefficient electronics.

These developments bolster U.S. leadership in materials innovation, energy technologies and secure communication, and they lay the groundwork for a future defined by leading-edge progress.

Shining a light on germs

Microbe hunters: Empa researchers Paula Bürgisser and Giacomo Reina from the Nanomaterials in Health laboratory in St. Gallen.
Photo Credit: Empa

Light on – bacteria dead. Disinfecting surfaces could be as simple as that. To turn this idea into a weapon against antibiotic-resistant germs, Empa researchers are developing a coating whose germicidal effect can be activated by infrared light. The plastic coating is also skin-friendly and environmentally friendly. A first application is currently being implemented for dentistry.

Antibiotic-resistant bacteria and emerging viruses are a rapidly increasing threat to the global healthcare system. Around 5 million deaths each year are linked to antibiotic-resistant germs, and more than 20 million people died during the COVID-19 virus pandemic. Empa researchers are therefore working on new, urgently needed strategies to combat such pathogens. One of the goals is to prevent the spread of resistant pathogens and novel viruses with smart materials and technologies.

Surfaces that come into constant contact with infectious agents, such as door handles in hospitals or equipment and infrastructure in operating theaters, are a particularly suitable area of application for such materials. An interdisciplinary team from three Empa laboratories, together with the Czech Palacký University in Olomouc, has now developed an environmentally friendly and biocompatible metal-free surface coating that reliably kills germs. The highlight: The effect can be reactivated again and again by exposing it to light.

Collection of tiny antennas can amplify and control light polarized in any direction

New polarization-independent, highly resonant metasurfaces can precisely amplify and control light without requiring incoming light (top left) to be oriented and traveling in a certain direction.
Image Credit: Bo Zhao

Antennas receive and transmit electromagnetic waves, delivering information to our radios, televisions, cell phones and more. Researchers in the McKelvey School of Engineering at Washington University in St. Louis imagines a future where antennas reshape even more applications.

Their new metasurfaces, ultra-thin materials made of tiny nanoantennas that can both amplify and control light in very precise ways, could replace conventional refractive surfaces from eyeglasses to smartphone lenses and improve dynamic applications such as augmented reality/virtual reality and LiDAR.

While metasurfaces can manipulate light very precisely and efficiently, enabling powerful optical devices, they often suffer from a major limitation: Metasurfaces are highly sensitive to the polarization of light, meaning they can only interact with light that is oriented and traveling in a certain direction. While this is useful in polarized sunglasses that block glare and in other communications and imaging technologies, requiring a specific polarization dramatically reduces the flexibility and applicability of metasurfaces.

Nanomaterials are emerging as a powerful tool for coastal oil spill cleanup

Oil Spill
Image Credit: Gemini 

Cleaning up after a major oil spill is a long, expensive process, and the damage to a coastal region’s ecosystem can be significant. This is especially true for the world’s Arctic region, where newly opened sea lanes will expose remote shorelines to increased risks due to an anticipated rise in sea traffic.

Current mitigation techniques even in heavily populated regions face serious limitations, including low oil absorption capacity, potential toxicity to marine life and a slow remediation process.

However, advances in nanotechnology may provide solutions that are more effective, safer and work much faster than current methods. That’s according to a new paper in Environmental Science: Nano by a Concordia-led team of researchers.

“Using nanomaterials as a response method has emerged as a promising sustainable approach,” says lead author Huifang Bi, a PhD candidate in the Department of Building, Civil and Environmental Engineering at the Gina Cody School of Engineering and Computer Science.