Researchers at the University of Waterloo are hoping to lighten the load for healthcare workers by developing a lightweight alternative to heavy lead aprons worn by X-ray technologists. The team has been working on the project for three years. The idea came up after a discussion with a radiologist about the weight of the lead aprons the technologists must wear all day long. “Many of them are forced to retire early because of the weight of the apron and the pain caused—mainly back pain,” explained Tizazu Mekonnen, a chemical engineering professor at the University of Waterloo and a Canada Research Chair in Sustainable Multiphase Polymers. Traditional aprons used for long periods can also shed toxic lead dust, which can be inhaled or ingested. That is why Mekonnen and PhD student Aklilu Messele set out to find a safer, lighter solution. The result of their research is a flexible polymer material that looks and feels nothing like a rigid metal plate. The science behind the shield “It’s very lightweight,” Mekonnen said. “It’s one-tenth of the weight of a lead apron.” Getting to this point took a lot of trial and error. The research team experimented with several heavy metals including bismuth, gadolinium, and barium before discovering that tungsten was the perfect candidate. To create the material, the team processes tungsten into rod-shaped nanoparticles. “This yellow thing is the nanoparticles, the tungsten nanoparticles,” Messele said, pointing to a flask. The process undergoes several phases before it can ever be turned into an apron. The nanoparticles are synthesized using a chemical precipitation technique, washed, and dried in an oven. “It’s incorporated into a silicone-based polymer or plastic, and can be shaped into the apron we are looking for,” Mekonnen said. By engineering the size, shape and arrangement of these nanoparticles into layers—called gradients, the team was able to keep the material highly flexible without sacrificing any radiation protection. What’s next? Now that the team has mastered the science, recently publishing their findings in the journal Materials Today Physics, the next step is scaling up to develop a commercial prototype. The team admitted that it might take some time for it to be at a clinic near you. “The next question would be that cost, right?” Mekonnen said. “It has to have a reasonable cost for it to be adopted by hospitals as well as clinics. So, we would not know that until we reach a stage where we start manufacturing. So those factors will determine how quickly we can get to the market.” The new material was already tested at Grand River Hospital in Kitchener. The research team is already looking beyond commercial use. They believe this lightweight material has potential for other shielding applications. One thing they are considering is using it to block gamma ray emissions. “Those are another kind of radiation with even more energy than X- rays. So usually, you can have gamma rays in nuclear facilities, for example,” said Messele.
