8 ADVANCED MATERIALS & PROCESSES | JANUARY/FEBRUARY 2025 studying the fiber-scale properties of parachute textiles. The team says that if the parachute’s performance is considered the macro scale, a bundle of fibers is the mesoscale, and an individual fiber represents the microscale. The goal was to quantify what was going on at those smaller scales and link that behavior to the forces happening on the larger scale. At each new level of force, micro-CT scans were taken while samples were kept under stress. Tensile testing showed how fibers stretched, straightened, and reorganized with increasing loads. As the fiber bundles changed shape, the pores between them widened, thus altering how air would flow through and around the parachute. When a textile has the same number of the same type of fibers going both directions, it is expected to be isotropic. However, the researchers observed that the textiles had different properties in different directions. During weaving, the fibers running in one direction (the warp) are held in tension on a loom, while the fibers running perpendicular to them (the weft) are slid in between the first set of fibers. Even after the textile is removed from the loom, the differences in tension TESTING | CHARACTERIZATION FASTER FAILURE DETECTION IMPROVES EV SAFETY Electric vehicles (EVs) have systems to detect performance issues with lithium-ion batteries. However, these systems are not focused on imminent safety concerns—like when the battery is about to catch on fire. Now, researchers at Sandia National Lab, Albuquerque, are working to detect these failures early and provide sufficient warning to vehicle occupants. Current measurements in battery management systems capture temperature and voltage, but these are lagging indicators of safety issues. The researchers are working on a diagnostic system that extends the warning period, allowing time to park and exit the vehicle. Their goal is to integrate this system into the car’s dashboard. To this end, the team is testing commercial off-the-shelf diagnostics on single cells and battery packs at the Battery Abuse Testing Laboratory. Beyond warning systems for EV batteries, the team says their techniques to detect failure markers have potential applications in grid energy storage systems. For now, researchers will continue to the next phase of their EV battery failure detection research—understanding the limitations and applying machine learning algorithms to datasets. Another focus area is advancing sensor technology to the point that the sensors issue more than warnings. “These tools can also activate mitigation measures,” explains researcher Loraine Torres-Castro. “For instance, upon receiving a warning, the system could trigger the thermal management system of the battery to start cooling it down.” sandia.gov. CT SCANS PROBE PARACHUTES Using computed tomography (CT) scans, researchers at the University of Illinois Urbana-Champaign are Triangular holes make this material more likely to crack from left to right. Courtesy of N.R. Brodnik et al./Phys. Rev. Lett. Tescan Group reopened its R&D facility in Tempe, Ariz., adding space to showcase the company’s latest electron microscopy technologies. The lab features the Tescan Tensor STEM and the new Solaris 2 FIB-SEM. Equipment demonstrations and support are available to customers in materials science and semiconductor R&D, failure analysis, and process monitoring. tescan.com. BRIEF From left: Francesco Panerai, Cutler Phillippe, and Laura Villafañe Roca utilize a micro-CT scanner at the Beckman Institute in their study of parachutes. Courtesy of Lauren Otolski/Beckman Communications Office. Sandia’s Alex Bates and Loraine Torres-Castro discuss the positioning of a battery that is being examined at the Battery Abuse Testing Lab. Courtesy of Craig Fritz.
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