ADVANCED MATERIALS & PROCESSES | MAY/JUNE 2025 12 EMERGING TECHNOLOGY NEW TOOL ANALYZES NANOPLASTICS An international team led by the University of Massachusetts Amherst developed a tool called OM-SERS (optical manipulation and surface-enhanced Raman scattering) to quantify the concentration of nanoplastics in a given sample, as well as detect the specific plastic types within it. The scientists say the tool can be used to detect nanoplastic concentrations and polymer types in samples such as soils, body tissues, and plants. “Because nanoplastics are so tiny, they have a much higher overall surface area and functional groups than microplastics, which means more of them can concentrate in water, soil, and body tissues,” says researcher Baoshan Xing. “They travel more easily and can wind up in more places in the environment and in our bodies. And once in those places, they are more reactive and the chemicals and additives in them can more easily leach out into their surroundings.” OM-SERS involves lasers, gold, and water. The researchers say it is the fastest, most efficient, and most reliable method yet developed to measure and analyze nanoplastics. OM-SERS begins with a water sample of just a few milliliters, into which the scientists place gold nanoparticles. Next, they shoot the nanoparticles with a laser and as the particles heat up, they attract the nanoplastics floating freely in the sample. Once the nanoplastic particles have flocked to the gold stack, the team rinses the sample with pure water, which flushes out the salts and any non-plastic debris. Left behind are tiny plastic particles gathered around a gold center, which may then be further analyzed. umass.edu. LIGHTSAILS FOR INTERSTELLAR TRAVEL Researchers from Brown University, Providence, R.I., and Delft University of Technology (TU Delft) in the Netherlands, developed a new way to design and fabricate ultrathin, ultra-reflective membranes for lightsails. In their new study, the team describes a lightsail membrane that is 60 mm wide by 60 mm long, but with a thickness of just 200 nm. The surface is patterned with billions of nanoscale holes, which help to reduce weight and increase reflectivity, giving the material more acceleration potential. Lightsails have the capacity to reduce flight time to nearby stars from several thousand years using current propulsion systems to just a decade or two. “The...fabrication process is scalable to the dimensions needed for interstellar travel and can be done in a cost-effective manner,” says Miguel Bessa, associate professor in Brown’s School of Engineering. The research is a big step toward realizing goals like those of the Starshot Breakthrough Initiative, founded by Yuri Milner and Stephen Hawking. The goal is to use ground-based lasers to power hundreds of meter-scale lightsails carrying microchip-sized spacecraft. For their design, the team used single-layer silicon nitride. The optimization process involved designing a pattern of nanoscale holes, billions of them across the material’s surface with diameters smaller than the wavelength of light. The scientists developed a new artificial intelligence method to adjust the shape and placement of holes. Once they arrived at the best design, the TU Delft team began fabricating it in the lab. Producing this lightsail with traditional methods would have been extremely pricey and taken as long as 15 years. With the new techniques, fabrication took a day and is thousands of times less expensive. brown.edu. Kraken Robotics Inc., Canada, acquired 3D at Depth Inc., Houston, a subsea services company specializing in high-resolution LiDAR imaging and measurements. The purchase complements Kraken’s suite of synthetic aperture sonar and sub-bottom imaging technologies. krakenrobotics.com. BRIEF The gold nanoparticle stack (GNS) is shown on left and nanoplastics on right. Courtesy of UMass Amherst. To obtain a sample’s reflectivity spectrum, a nanowafer with a suspended photonic crystal membrane is clamped in the measurement setup. Courtesy of TU Delft and Brown University.
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