Tag Archives: Stella Batalama

A nanoscale look inside a blacktip shark’s skeleton reveals ‘sharkitecture’

It’s usually sharkskin that excites scientific attention. (It has nanoscale structures that endow it with special properties See: “Characterization of shark skin properties and biomimetic replication” published July 15, 2024). This May 20, 2025 news item on ScienceDaily shifts attention to the skeleton,

Sharks have been evolving for more than 450 million years, developing skeletons not from bone, but from a tough, mineralized form of cartilage. These creatures are more than just fast swimmers — they’re built for efficiency. Their spines act like natural springs, storing and releasing energy with each tailbeat, allowing them to move through the water with smooth, powerful grace.

Now, scientists are peering inside shark skeletons at the nanoscale, revealing a microscopic “sharkitecture” that helps these ancient apex predators withstand extreme physical demands of constant motion.

A May 20, 2025 Florida Atlantic University (FAU) news release (also on EurekAlert) by Gisele Galoustian, which originated the news item, delves further into the topic, Note: Links have been removed,

Using synchrotron X-ray nanotomography with detailed 3D imaging and in-situ mechanical testing, researchers from the Charles E. Schmidt College of Science and the College of Engineering and Computer Science at Florida Atlantic University, in collaboration with the German Electron Synchrotron (DESY) in Germany, and NOAA [US National Oceanic and Atmospheric Administration] Fisheries, have mapped the internal structure of blacktip sharks (Carcharhinus limbatus) in unprecedented detail.

Results of the study, published in ACS ]American Chemical Society] Nano, reveal two distinct regions within the blacktip shark’s mineralized cartilage: the corpus calcareum and the intermediale. Though both are composed of densely packed collagen and bioapatite, their internal structures differ significantly. In both regions, mineralized plates are arranged in porous structures, reinforced by thick struts that help the skeleton withstand strain from multiple directions – a critical adaptation for sharks, whose constant swimming places repeated stress on the spine.

At the nanoscale, researchers observed tiny needle-like bioapatite crystals – a mineral also found in human bones – aligned with strands of collagen. This intricate structure gives the cartilage surprising strength while still allowing flexibility.

Even more intriguing, the team discovered helical fiber structures primarily based on collagen – suggesting a sophisticated, layered design optimized to prevent cracks from spreading. Under strain, fiber and mineral networks work together to absorb and distribute force, contributing to the shark’s resilience and flexibility.

“Nature builds remarkably strong materials by combining minerals with biological polymers, such as collagen – a process known as biomineralization. This strategy allows creatures like shrimp, crustaceans and even humans to develop tough, resilient skeletons,” said Vivian Merk, Ph.D., senior author and an assistant professor in the FAU Department of Chemistry and Biochemistry, the FAU Department of Ocean and Mechanical Engineering, and the FAU Department of Biomedical Engineering. “Sharks are a striking example. Their mineral-reinforced spines work like springs, flexing and storing energy as they swim. By learning how they build such tough yet adaptable skeletons, we hope to inspire the design of next-generation materials.” 

In experiments applying mechanical stress on microscopic samples of shark vertebrae, the researchers observed tiny deformations – less than a micrometer – after a single cycle of applied pressure. Interestingly, fractures only occurred after a second round of loading and were contained within a single mineralized plane, hinting at the material’s built-in resistance to catastrophic failure.

“After hundreds of millions of years of evolution, we can now finally see how shark cartilage works at the nanoscale – and learn from them,” said Marianne Porter, Ph.D., co-author and an associate professor in the FAU Department of Biological Sciences. “We’re discovering how tiny mineral structures and collagen fibers come together to create a material that’s both strong and flexible, perfectly adapted for a shark’s powerful swimming. These insights could help us design better materials by following nature’s blueprint.”

Found in warm, shallow coastal waters worldwide, blacktip sharks are sleek, fast-swimming predators known for their incredible agility and speed, reaching up to 20 miles per hour. One of the most striking behaviors they display is leaping and spinning out of the water, often during feeding – an acrobatic move that adds to their mystique.

This research not only enhances the biomechanical understanding of shark skeletons but also offers valuable insights for engineers and materials scientists. 

“This research highlights the power of interdisciplinary collaboration,” said Stella Batalama, Ph.D., dean of the College of Engineering and Computer Science. “By bringing together engineers, biologists and materials scientists, we’ve uncovered how nature builds strong yet flexible materials. The layered, fiber-reinforced structure of shark cartilage offers a compelling model for high-performance, resilient design, which holds promise for developing advanced materials from medical implants to impact-resistant gear.”

Study co-authors are Dawn Raja Somu, Ph.D.; and Steven A. Soini, Ph.D., two recent Ph.D. graduates from the Charles E. Schmidt College of Science; Ani Briggs, a former undergraduate student in the FAU College of Engineering and Computer Science; Kritika Singh, Ph.D.; and Imke Greving, Ph.D., scientists at outstations of the DESY PETRA III X-ray light source operated by Helmholtz-Zentrum Hereon; and Michelle Passerotti, Ph.D., a research fish biologist at NOAA Fisheries.

This research was supported by a National Science Foundation (NSF) grant awarded to Merk; an NSF CAREER Award, awarded to Porter; and seed funding from the FAU College of Engineering and Computer Science and FAU Sensing Institute (I-SENSE). The acquisition of a transmission electron microscope was supported by a United States Department of Defense instrumentation/equipment grant awarded to Merk.

Caption: An X-ray nanotomography reconstruction of the intermedial cartilage of a blacktip shark. The colors indicate the thickness of the struts, with red representing thicker areas and blue indicating thinner ones. Credit: Florida Atlantic University

Here’s a link to and a citation for the paper,

A Nanoscale View of the Structure and Deformation Mechanism of Mineralized Shark Vertebral Cartilage by Dawn Raja Somu, Steven A. Soini, Ani Briggs, Kritika Singh, Imke Greving, Marianne Porter, Michelle Passerotti, and Vivian Merk. ACS Nano 2025, 19, 14, 14410–14421 DOI: https://doi.org/10.1021/acsnano.5c02004 Published April 7, 2025 Copyright © 2025 American Chemical Society

This paper is behind a paywall.

Fortify wood with eco-friendly nano-iron

An April 28, 2025 news item on ScienceDaily announced an investigation into making wood stronger,

Scientists and engineers are developing high-performance materials from eco-friendly sources like plant waste. A key component, lignocellulose — found in wood and many plants — can be easily collected and chemically modified to improve its properties.

By using these kinds of chemical changes, researchers are creating advanced materials and new ways to design and build sustainably. With about 181.5 billion tons of wood produced globally each year, it’s one of the largest renewable material sources.

Researchers from the College of Engineering and Computer Science at Florida Atlantic University, and collaborators from the University of Miami and Oak Ridge National Laboratory, wanted to find out if adding extremely hard minerals at the nanoscale could make the walls of wood cells stronger — without making the wood heavy, expensive or bad for the environment. Few studies have investigated how treated wood performs at different scales, and none have successfully strengthened entire pieces of wood by incorporating inorganic minerals directly into the cell walls.

Caption: A microCT image that shows the distribution of the iron mineral in the wood cell wall (in turquoise). Credit: Florida Atlantic University

An April 28, 2025 Florida Atlantic University (FAU) news release (also on EurekAlert) by Gisele Galoustian, which originated the news item, provides more technical details about the work,Note: Links have been removed,

The research team focused on a special type of hardwood known as ring-porous wood, which comes from broad-leaf trees like oak, maple, cherry and walnut. These trees feature large, ring-shaped vessels in the wood that transport water from the roots to the leaves. For the study, researchers used red oak, a common hardwood in North America, and introduced an iron compound into the wood through a simple chemical reaction. By mixing ferric nitrate with potassium hydroxide, they created ferrihydrite, an iron oxide mineral commonly found in soil and water.

Results of the study, published in the journal ACS Applied Materials and Interfaces, revealed that a simple, cost-effective chemical method using a safe mineral called nanocrystalline iron oxyhydroxide can strengthen the tiny cell walls within wood while adding only a small amount of extra weight. Although the internal structure became more durable, the wood’s overall behavior – such as how it bends or breaks – remained largely unchanged. This is likely because the treatment weakened the connections between individual wood cells, affecting how the material holds together on a larger scale.

The findings suggest that, with the right chemical treatment, it’s possible to enhance the strength of wood and other plant-based materials without increasing their weight or harming the environment. These bio-based materials could one day replace traditional construction materials like steel and concrete in applications such as tall buildings, bridges, furniture and flooring.

“Wood, like many natural materials, has a complex structure with different layers and features at varying scales. To truly understand how wood bears loads and eventually fails, it’s essential to examine it across these different levels,” said Vivian Merk, Ph.D., senior author and an assistant professor in the FAU Department of Ocean and Mechanical Engineering, the FAU Department of Biomedical Engineering, and the FAU Department of Chemistry and Biochemistry within the Charles E. Schmidt College of Science. “To test our hypothesis – that adding tiny mineral crystals to the cell walls would strengthen them – we employed several types of mechanical testing at both the nanoscale and the macroscopic scale.”

For the study, researchers used advanced tools like atomic force microscopy (AFM) to examine the wood at a very small scale, allowing them to measure properties such as stiffness and elasticity. Specifically, they employed a technique called AM-FM (Amplitude Modulation – Frequency Modulation), which vibrates the AFM tip at two different frequencies. One frequency generates detailed surface images, while the other measures the material’s elasticity and stickiness. This method gave them a precise view of how the wood’s cell walls were altered after being treated with minerals.

Additionally, the team conducted nanoindentation tests within a scanning electron microscope (SEM), where tiny probes were pressed into the wood to measure its response to force in different areas. To round out their analysis, they performed standard mechanical tests – such as bending both untreated and treated wood samples – to evaluate their overall strength and how they broke under stress.

“By looking at wood at different levels – from the microscopic structures inside the cell walls all the way up to the full piece of wood – we were able to learn more about how to chemically improve natural materials for real-world use,” said Merk.

This combination of small- and large-scale testing helped the researchers understand how the treatment affected both the fine details inside the cell walls and the overall strength of the wood.

“This research marks a significant advancement in sustainable materials science and a meaningful stride toward eco-friendly construction and design,” said Stella Batalama, Ph.D., the dean of the College of Engineering and Computer Science. “By reinforcing natural wood through environmentally conscious and cost-effective methods, our researchers are laying the groundwork for a new generation of bio-based materials that have the potential to replace traditional materials like steel and concrete in structural applications. The impact of this work reaches far beyond the field of engineering – it contributes to global efforts to reduce carbon emissions, cut down on waste, and embrace sustainable, nature-inspired solutions for everything from buildings to large-scale infrastructure.”

Study co-authors are Steven A. Soini, a Ph.D. graduate from the FAU College of Engineering and Computer Science and FAU Charles E. Schmidt College of Science; Inam Lalani, a Ph.D. student at the University of Miami; Matthew L. Maron, Ph.D., a doctoral researcher at the University of Miami; David Gonzalez, a graduate student in the FAU College of Engineering and Computer Science; Hassan Mahfuz, Ph.D., a professor in the FAU Department of Ocean and Mechanical Engineering; and Neus Domingo-Marimon, Ph.D., senior R&D staff scientist, group leader for the Functional Atomic Force Microscopy Group, Oak Ridge National Laboratory.

Here’s a link to and a citation for the paper,

Multiscale Mechanical Characterization of Mineral-Reinforced Wood Cell Walls by Steven A. Soini, Inam Lalani, Matthew L.Maron, David Gonzalez, Hassan Mahfuz, Neus Domingo-Marimon, Vivian Merk. ACS Applied Materials & Interfaces (ACS Appl. Mater. Interfaces) 2025, 17, 12, 18887–18896 DOI: https://doi.org/10.1021/acsami.4c22384 Published: March 12, 2025 Copyright © 2025 American Chemical Society

This paper is behind a paywall.

One last comment, I love wordplay, so I offer my thanks to Gisele Galoustian for the news release’s original title “‘Wood you believe it?’ FAU engineers fortify wood with eco-friendly nano-iron.”