As scientists continue to push the boundaries of innovation, researchers at Tohoku University have made a groundbreaking discovery in the realm of electrocatalysis. They have successfully demonstrated that applying an external magnetic field can significantly enhance the performance of single-atom catalysts (SACs), leading to a staggering 2,880% improvement in oxygen evolution reaction magnetocurrent.

This revolutionary finding has far-reaching implications for various industries, particularly those involving ammonia production and wastewater treatment. Traditionally, electrocatalysis focused on tweaking the chemical composition and structure of catalysts. However, the introduction of magnetic-induced spin state modulation offers a new dimension for catalyst design and performance improvement.

By regulating the electronic spin state of the catalyst through an external magnetic field, researchers can precisely control the adsorption and desorption processes of reaction intermediates. This, in turn, reduces the activation energy of the reaction, allowing it to proceed more quickly. As explained by Hao Li of Tohoku University’s Advanced Institute for Materials Research (WPI-AIMR), “More efficient production processes can reduce costs, which may translate into lower prices for products such as fertilizers and treated water at the consumer level.”

The study employed advanced characterization techniques to confirm that the magnetic field causes a transition to a high spin state, which improves nitrate adsorption. Theoretical analysis also revealed the specific mechanics behind why this spin state transition enhances electrocatalytic ability.

In an experiment conducted with a Ru-N-C electrocatalyst exposed to an external magnetic field, researchers achieved a remarkable NH3 yield rate (~38 mg L-1 h-1) and a Faradaic efficiency of ~95% for over 200 hours. This represents a significant improvement compared to the same catalyst without the boost from an external magnetic field.

This groundbreaking work enriches our theoretical understanding of electrocatalysis by exploring the relationship between magnetic fields, spin states, and catalytic performance. The experimental results offer valuable insights for future research and development of new catalysts, paving the way for practical applications in electrochemical technologies.

The University of Nebraska-Lincoln engineering team has made significant strides in developing soft robotics and wearable systems inspired by human and plant skin’s ability to self-heal injuries. Led by engineer Eric Markvicka, the team presented a groundbreaking paper at the IEEE International Conference on Robotics and Automation that showcased their innovative approach to creating an intelligent, self-healing artificial muscle.

The team’s strategy overcomes the long-standing problem of replicating traditional rigid systems using soft materials and incorporating nature-inspired design principles. Their multi-layer architecture enables the system to identify damage, pinpoint its location, and autonomously initiate a self-repair mechanism – all without external intervention.

The “muscle” or actuator features three layers: a damage detection layer composed of liquid metal microdroplets embedded in silicone elastomer, a self-healing component that uses thermoplastic elastomer to seal the wound, and an actuation layer that kick-starts the muscle’s motion when pressurized with water.

To begin the process, the team induces monitoring currents across the damage detection layer, which triggers formation of an electrical network between traces. Puncture or pressure damage causes this network to form, allowing the system to recognize and respond to the damage.

The next step is using electromigration – a phenomenon traditionally viewed as a hindrance in metallic circuits – to erase the newly formed electrical footprint. By further ramping up the current, the team can induce electromigration and thermal failure mechanisms that reset the damage detection network, effectively completing one cycle of damage and repair.

This breakthrough has far-reaching implications for various industries, particularly in agricultural states where robotics systems frequently encounter sharp objects. It could also revolutionize wearable health monitoring devices that must withstand daily wear and tear.

The technology has the potential to transform society more broadly by reducing electronic waste and mitigating environmental harm caused by consumer-based electronics’ short lifespans. Most consumer electronics have a lifespan of only one or two years, contributing billions of pounds of toxic waste each year.

“If we can begin to create materials that are able to passably and autonomously detect when damage has happened, and then initiate these self-repair mechanisms, it would really be transformative,” Markvicka said.

The current regulations for nanomedicines have a significant blind spot when it comes to evaluating the different forms of an element, such as ions, nanoparticles, and aggregates. A recent study by Japanese researchers has developed a new analytical method that combines asymmetric flow field-flow fractionation (AF4) and mass spectrometry to separately quantify these forms. This technique allows for better quality control and safety evaluation of metal-based nanomedicines, promoting their development and clinical use.

Nanomedicines, especially those based on nanoparticles, are revolutionizing healthcare in terms of both diagnostics and therapeutics. These particles can serve as contrast agents in medical imaging, act as nutritional supplements, and even function as carriers for drug delivery. However, the same characteristics that make nanomedicines valuable also present challenges in ensuring their safety and quality.

The researchers combined two existing technologies – AF4 and inductively coupled plasma mass spectrometry (ICP-MS) – to develop a new analytical method. They used the AF4 method in a novel way, taking advantage of its initial ‘focus step.’ During this step, particles are held inside the AF4 channel by two opposing flows. Using a special permeable membrane, cross-flows filter out the tiniest dissolved particles (ions), enabling quantification based on the differences in ICP-MS signals between samples with and without ion removal.

The researchers tested their approach on Resovist®, a nanomedicine used as a contrast agent in liver magnetic resonance imaging scans. The analysis revealed that only 0.022% of the iron in Resovist® was present in ionic form, which falls well below levels of concern. Additionally, the team confirmed that the active nanoparticles were smaller than 30 nanometers in diameter, with some aggregates around 50 nanometers.

The proposed technique is particularly relevant for emerging cancer treatments that use gold nanoparticles as drug delivery systems or metallic particles for photothermal therapy. This advanced treatment relies on the ‘enhanced permeability and retention (EPR) effect,’ by which nanoparticles leak from blood vessels around tumors and accumulate in cancerous tissue.

This novel analytical approach extends beyond pharmaceuticals, assessing the safety of metal nanoparticles in food additives, cosmetics, and environmental samples – helping to ensure public health across multiple sectors. The researchers showcased its versatility by successfully analyzing both negatively charged ions (silicon) and positively charged ions (iron).

Overall, by offering a more comprehensive assessment of the composition, quality, and stability of nanoparticles, this research paves the way for safer and more effective nanomedicines and nanoparticle-based technologies.