Uncover reality

Imagine a material that can be soft along one edge, extremely stiff along another, and capable of changing between these states simply by applying a small deformation. Even more surprising, this transformation can happen without requiring large forces or significant energy. This is the remarkable idea behind transformable topological mechanical metamaterials (TTMMs) —engineered structures whose geometry, rather than their chemical composition, determines how they respond to forces, vibrations and motion. Researchers including Rocklin and his team have shown that carefully designed mechanical lattices can be reversibly transformed between states with dramatically different mechanical and acoustic properties. During this transformation, properties such as edge stiffness and the speed at which sound travels through the material can change by orders of magnitude. The work brings together three fascinating areas of physics: mechanical metamaterials, soft deformation and topology . What Are...

Scientists have discovered a remarkably simple way to create continuous rotary motion using nothing more than an elastic polymer fibre, its carefully designed geometry, and heat. The new concept could eventually contribute to the development of intelligent materials, artificial muscles, soft robots and self-propelled mechanical systems. Researchers from Heidelberg University in Germany and the University of Strasbourg in France have demonstrated how a prestrained polymer fibre, closed into a ring, can spontaneously rotate when exposed to a temperature difference. Unlike conventional motors, the system does not depend on a rigid wheel, axle, gears or complicated machinery. The findings, published in Nature Materials , demonstrate how the geometry and mechanical properties of a material can themselves perform functions normally associated with machines. A Motor Without a Conventional Wheel and Axle Most rotary machines depend on a familiar combination: a wheel rotates around an axle. F...

For decades, astronomers have hoped that some of the most unusual structures surrounding the Milky Way could help reveal one of the universe’s greatest mysteries: dark matter . Dark matter cannot be seen directly because it does not appear to interact with light. Yet scientists believe it makes up most of the matter in the universe and plays a major role in shaping galaxies. One of the most promising tools for investigating it has been stellar streams —long, thin bands of stars that orbit the Milky Way. Their unusual gaps, bends and clumps have often been interpreted as possible evidence of invisible concentrations of dark matter. But a new study from the University of Washington suggests that astronomers may need to be more careful. Published August 27 in The Astrophysical Journal , the study found that the Milky Way itself could create many of the strange features seen in stellar streams—even without the presence of dark matter clumps. What Are Stellar Streams? Most stars in the Mil...

Venus is often called Earth’s “evil twin,” but its atmosphere hides a mystery that has puzzled scientists for nearly a century. From space, the planet appears pale yellow and relatively featureless in visible light. But when Venus is observed in ultraviolet wavelengths, its upper atmosphere reveals striking dark and bright patterns that move with the planet’s clouds. These patterns are associated with Venus’s thick clouds of sulfuric acid droplets. Scientists have long suspected that an unidentified substance inside these clouds absorbs ultraviolet and blue light. Yet despite decades of research, the exact identity of this mysterious material—often called the “unknown absorber” —remains unknown. Now, an international team of researchers has taken an important step toward solving the puzzle. Instead of simply asking what substance could create Venus’s dark ultraviolet markings, the scientists calculated how strongly the cloud material must absorb light to reproduce what telescopes obse...

As humanity prepares for longer space missions, including future journeys to the Moon and Mars, scientists are discovering that spaceflight may affect the human body in ways that are still poorly understood. Now, researchers have identified a potential new concern for women: changes in the vaginal microbiome caused by the physical and psychological stresses of space travel. In a first-of-its-kind study, researchers led by Begum Mathyk, MD , a physician-scientist in the Department of Obstetrics and Gynecology at the USF Health Morsani College of Medicine, investigated how altered gravity and spaceflight-related stress affect the vaginal microbiome. Published in Frontiers in Microbiology , the study found that parabolic flight can produce short-term physiological stress and cause measurable changes in the vaginal microbiome. Interestingly, the effects were much stronger in the vaginal microbiome than in the oral microbiome. The findings could become increasingly important as space agenci...

Imagine a tiny robot that does not need a motor, battery, gears or complicated electronics to jump. Shine infrared light on it, and it can repeatedly leap into the air, land, return to its original shape and jump again—all without needing an external mechanism to reset it. That is the remarkable behavior demonstrated by researchers at North Carolina State University (NC State), who have developed teardrop-shaped soft robots capable of crawling, jumping forward or even leaping vertically depending on their shape. The research, published in the Proceedings of the National Academy of Sciences , introduces a simple but powerful mechanism for creating self-resetting jumping motion in soft robots . Although the technology is still at the proof-of-concept stage, it could eventually contribute to robots designed to move across difficult and unpredictable environments. A Robot That Uses Light Instead of a Motor The new robot, described as a “ring leaper,” has an unusually simple structure. It ...

What if the heat produced by a computer, car engine, industrial machine or even sunlight could be used to create cooling instead of simply being released into the environment? Scientists from the Karlsruhe Institute of Technology (KIT) in Germany and the University of Tsukuba in Japan have demonstrated a new cooling technology that could make this idea possible. In a prototype system, researchers used two ultra-thin nickel-titanium shape-memory films to convert heat into mechanical motion and then into cooling . The concept could eventually lead to compact, electricity-free cooling systems powered by waste heat or solar energy. The research has been published in Nature Energy . Why Do We Need a New Way to Cool Things? Cooling is essential in modern life. Refrigerators preserve food, air-conditioning systems keep buildings comfortable, and data centers depend on powerful cooling systems to prevent computers and servers from overheating. However, conventional cooling technology has a m...