Oobleck's Surprising Behavior Under Impact Revealed

United States - Ekhbary News Agency

Scientists at the University of Minnesota have unveiled novel findings regarding the behavior of non-Newtonian fluids, specifically the substance famously known as "oobleck." This simple yet fascinating mixture of cornstarch and water exhibits characteristics of both a liquid and a solid, depending on the applied force. In a recent study published in Physical Review Letters, researchers employed high-speed imaging and force sensors to analyze the dynamics of oobleck drops impacting a flat surface. The observations revealed that while less concentrated drops behaved predictably, dense drops experiencing high shear rates displayed paradoxical behavior: they momentarily spread like a Newtonian liquid before instantaneously hardening into a solid state. This discovery holds significant implications for understanding the complex physics of non-Newtonian fluids, with potential applications in areas such as 3D printing, soft robotics, and industrial coatings. The researchers emphasize that this work sheds light on the unusual behavior of shear-thickening fluids under ultrafast deformation, offering a more comprehensive understanding of the impact dynamics of oobleck drops.

Non-Newtonian fluids, unlike their Newtonian counterparts, alter their viscosity in response to applied stress. This means their behavior doesn't follow simple viscosity laws dependent solely on temperature and pressure. Ketchup, yogurt, and oobleck itself are common examples. The study of oobleck continues, with prior research, such as that from the University of Chicago, utilizing nanoparticles to probe molecular transitions between liquid and solid states. Other researchers at the University of California, Merced, have developed polymer films that toughen upon impact, mimicking oobleck's behavior and opening avenues for impact-resistant electronic devices.

Ekhbary News Agency