Last January, in the waters off Cebu City in the Philippines, researchers first deployed a huge flexible ring seeded with seaweed and spanned by spokelike ropes and tubes. Every nightfall, cranks mounted on a floating platform lower the ring 25 meters below the surface to expose the seaweed to cooler, more nutrient-rich water. At daybreak, the cranks pull the ring back up to the surface to soak up sunlight and carbon dioxide.

Replacing waning batteries in implantable medical devices usually means invasive surgery. A new battery designed to run on the body's oxygen and tested in rats hints at a way to power medical sensors and simulators for much longer than is possible with existing batteries ( Chem 2024, DOI: 10.1016/j.chempr.2024.02.012 ). Batteries are the best option available today for powering implantable electronics. But they have limited lifetimes. So researchers have been trying to develop devices that generate power via chemical reactions with glucose or enzymes found in the body. Xizheng Liu of Tianjin University of Technology, Pingli Wu of Hebei University, Yonggang Wang of Fudan University, and colleagues decided to use the body's oxygen as a continuous energy source in a metal-oxygen battery. Metal-oxygen batteries have theoretical energy densities 5–10 times greater than the lithium-based implantable batteries used today, Liu says. The soft, flexible battery has an anode made of a

A strong, stretchy hydrogel adhesive tightly seals protective nervous system tissue better than commercially available glues and could help prevent complications from neurosurgery ( Sci. Transl. Med. 2024, DOI: 10.1126/scitranslmed.adj0616 ). Up to one-third of patients undergoing neurosurgery can experience complications due to leakage of the protective cerebrospinal fluid that surrounds the brain and spinal cord. Surgeons prevent such leaks by suturing the dense dural membrane that covers the nervous system. Because it can be challenging to create a leak-proof seal with sutures, surgeons often also use glues. But existing dural glues do not adhere strongly to wet tissue , and they fracture easily, says Benjamin Freedman , a bioengineer at Harvard University. Freedman, Kyle Wu of the Ohio State University, David Mooney of Harvard, and their colleagues turned to an adhesive inspired by slug mucus and developed in Mooney's lab. The two-part adhesive consists of a tough hydrogel made

Sometimes engineers just want to have fun. And that fun can yield useful insights. In an elegant example, researchers have translated the motion of ions and molecules at the interface between an electrode and electrolyte into audible sound ( ACS Cent. Sci. 2024, DOI: 10.1021/acscentsci.3c01253 ). Electrode-electrolyte interfaces are the work center of batteries, electrolyzers, and electrochemical sensors. The molecular interactions at these interfaces are invisible, says Marcel Schreier , a chemical and biological engineering professor at the University of Wisconsin–Madison. Giving voice to the interface yields a "direct, quick, and intuitive probe into its behavior," he says. Schreier and colleagues started with a sound-generating electronic circuit. Capacitors in the circuit charge and discharge, producing a waveform that speakers convert to sound. The electrode-electrolyte interface has a capacitance that depends on the configuration of its ions and molecules. So the team swapped the circuit's capacitor with an electrode placed in

Mussels, barnacles, and other sticky marine invertebrates have been many a researcher's inspiration for designing novel adhesives . A new study shows for the first time that the proteins in the natural adhesive of barnacles are good at preventing the corrosion of metals in seawater ( Commun. Mater. 2024, DOI: 10.1038/s43246-024-00445-z ). This finding could aid the development of environmentally friendly anticorrosion paints and coatings . Metal surfaces of boats and offshore rigs are coated with corrosion-inhibiting compounds to protect them in the high-salt environment of the sea. Commercial inhibitors made from organic compounds such as azoles, amines, and phenols form tough films on metal surfaces, preventing exposure to seawater, but they can leach toxic chemicals into the environment. Because barnacles cling to underwater metal surfaces, researchers at Nanyang Technological University investigated whether the crustaceans' adhesive proteins could form an impenetrable protective layer on metal. The team genetically engineered bacteria

Mining metals for lithium-ion batteries carries environmental and ethical concerns . To make batteries more sustainable and to reduce costs , carmakers are trying new strategies, including cutting the amount of cobalt in cathodes and adopting chemistries like lithium iron phosphate (LFP). Metal-free organic cathodes would be an ideal alternative, but their performance has been lackluster. Researchers now report an organic cathode material with performance that matches state-of-the-art lithium-ion cathodes. The material, initially reported on the preprint server ChemRxiv (2023, DOI: 10.26434/chemrxiv-2023-j91zf ), can hold as much energy as commercial cobalt- and nickel-based cathodes, can charge in minutes, and boasts a lifetime of over 2,000 recharge cycles; today's EV batteries typically last 1,000–1,500 cycles ( ACS Cent. Sci. 2024, DOI: 10.1021/acscentsci.3c01478 ). The new material, bis-tetraaminobenzoquinone, is also "super easy to make [using] organic precursors that are commodity chemicals made on a million-kilogram scale," says Mircea Dincă , a chemist

Chemistry adventures Aside from the laboratory, the outdoors is Erin Joy Araneta 's favorite place to be. When the pandemic hit, she found herself with more time to hike, paddle, and rock climb . . . and to reflect. Chemistry was at work all around her— in the water, air, and rocks. How could she foster children's natural curiosity about it? "I wanted to help kids see how cool chemistry is," says Araneta, a chemistry graduate student at the University of Southern California. As the idea of a book aimed at her 6-year-old cousin—who she describes as "a very spicy girl"—took shape in her mind, she knew the nerdy male stereotype of chemists needed to go. "I wanted a fun, bubbly character who's relatable," she tells Newscripts. And so, Chemist Clara was born. Think Dora the Explorer but with a backpack and brain full of chemistry tools and tricks to

Lithium has reigned in the battery world for decades. Researchers have tried for years to make a cheaper, more sustainable successor to lithium-ion batteries by using the element's more common neighbors on the periodic table. Sodium batteries are gaining ground, and commercialization is underway. Research on potassium and magnesium batteries is also making steady progress. Yet when it comes to abundance and cost, calcium takes the crown . The third-most abundant metal, after iron and aluminum, calcium is present most everywhere in Earth's crust. By contrast, the main metals used in lithium-ion batteries—lithium, nickel, and cobalt—are concentrated in certain geographical regions, which makes them expensive and where mining them is often hard on people and the environment. Scientists first toyed with calcium-based batteries in the 1960s. But they worked only at high temperatures and fizzled out after just a handful of charge cycles. "It's very difficult to get calcium to

Researchers at Drexel University discovered MXenes, a new family of 2D materials, in 2010. The scientists soon found ways to prepare what seemed like endless chemical compositions of these materials, many with unique properties. Now studied by researchers worldwide, MXenes may soon play a transformative role in energy storage, electronics, optics, biomedicine, and catalysis. Many companies have MXene licenses and patents, and companies are on the verge of launching the first commercial products. But to make a real impact, researchers must tailor MXenes to improve their chemical stability and identify ways to manufacture them inexpensively at large scale. Michael Naguib remembers with humor and humility the day he accidentally discovered a remarkable new material. It was a hot August morning in 2010. Naguib, a PhD student at Drexel University, had been wrangling a material called a MAX phase, trying to make it work as a lithium-ion battery electrode. But the

Soon after the 2024 Major League Baseball (MLB) season started in March, sweat stains began to bloom along with spring flowers. Sweat seemed to be soaking through the gray uniform jerseys that team members wear when they play away from home, turning them visibly dark. Synthetic sports performance fabrics are designed to help keep their wearers comfortable and fresh. So what went wrong with the new, highly engineered Nike Vapor Premier baseball uniforms? C&EN asked textile researchers to speculate, and they had fun doing it. "Textile structures are incredibly complex, and when you add chemical finishes, the degree of complexity multiplies," says Juan Hinestroza , professor of fiber science and apparel design at Cornell University. So the answer to what possibly went wrong is "all of the above," he says. MLB and Nike claim that the new uniforms are made from at least 90% recycled polyester yarns, have Nike's proprietary

A new power generator concept could let people charge fitness trackers and smartwatches with their own perspiration ( Device 2024, DOI: 10.1016/j.device.2024.100356 ). The flexible generator, which could be embedded in a wristband or headband, harnesses energy from evaporating sweat and produces electricity. The device is a type of hydroelectric nanogenerator (HENG). "Its working mechanism is pretty fascinating," says Jingliang Li , a chemical engineer at Deakin University. HENGs have porous substrates loaded with functional materials that absorb water and split it into positive and negative ions, which line up along the substrate's channels. As some water evaporates, capillary force drives more water past the charged channel walls, generating an electric current. Researchers have made similar generators before using carbon particles or nanotubes, but the output power has been low because the particles clump together. Li, Azadeh Nilghaz , and colleagues used MXenes, which are 2D layered transition- metal carbides