RAPID: Current and Next Generation Mask Elastomer Straps: Mechanical Integrity with Sterilization and Reuse

这项2019冠状病毒病快速反应研究（Rapid）赠款将调查卫生保健工作者使用的个人防护装备的消毒和重复使用策略如何影响口罩带的性能。一次性N95和其他口罩在美国和全球都供不应求，这激发了人们对其消毒和重复使用的兴趣。除了灭菌程序杀死病毒外，重要的是口罩保留了已知的部分功能，包括多次灭菌的机械耐用性。灭菌处理有可能降解口罩材料，特别是弹性带，这在初步研究中已被确定为薄弱环节。该项目将通过研究各种灭菌处理对绑带材料的结构和性能的影响，为这一重要的全球需求做出贡献，以确保安全可靠地安装口罩，这些口罩在处置前将被重复使用有限次数。此外，低收入和中等收入国家将需要在该项目中开发的技术，这些技术将超越当前的危机，并将在未来几年影响全世界的紧急护理情况。这项工作的目标是将灭菌处理的类型和程度与弹性体带的性能相关联。为了实现这一目标，将进行材料表征实验，以建立材料结构和性能变化与所使用的灭菌方法和与穿脱和落纱相关的机械变形的综合影响之间的联系。具体而言，化学变化将使用热和光谱方法进行评估，这些方法量化变化的程度和空间分布作为暴露剂量和时间的函数。粘弹性和机械性能的补充测试将评估因灭菌而导致的性能变化。除了对绑带进行表征外，还将使用机械测试来测量与口罩连接的完整性。这项工作的结果将为每种灭菌方法提供更完整的条带降解理解，从而为灭菌工艺和掩膜组件的设计提供信息，以优化有效的掩膜寿命。此外，如果这项工作得出结论，带状完整性是给定N95掩膜寿命的限制因素，了解这些潜在的失效机制将为开发可行的材料替代品或修改提供见解，可以延长整体掩膜寿命。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This COVID-19 Rapid Response Research (RAPID) grant will investigate how sterilization and reuse strategies for personal protective equipment used by healthcare workers affect the properties of mask straps. Single use N95 and other masks are in short supply in the US and globally, which has stimulated interest in their sterilization and reuse. In addition to the sterilization procedure killing viruses, it is important that the mask retains a known fraction of functionality including mechanical durability over multiple sterilizations. Sterilization treatments have the possibility of degrading mask materials, in particular elastic straps, which have been identified as a weak link in initial studies. This project will contribute to this important, global need by studying the effects of various sterilization treatments on the structure and properties of strap materials to ensure safe and reliable fitting of masks that will be reused a limited number of times prior to disposal. Additionally, there will be a need for technology developed in this project in low to middle income countries that transcends the immediate crisis and will impact emergency care situations world-wide for years to come.The goal of this work is to correlate the type and extent of sterilization treatment with the properties of the elastomeric straps. To accomplish this, materials characterization experiments will be performed that establish links between changes in material structure and properties to the combined effects of the sterilization method used and the mechanical deformation associated with donning and doffing. Specifically, chemical changes will be evaluated using thermal and spectroscopic methods that quantify the extent and the spatial distribution of the changes as a function of exposure dose and time. Complementary testing of viscoelastic and mechanical properties will evaluate changes in performance because of sterilization. Beyond characterization of the straps, the integrity of the attachment to the mask will be measured using mechanical testing. The results of this work will provide a more complete understanding of strap degradation for each sterilization method, thereby informing the design of sterilization processes and mask components to optimize the effective mask lifetime. Furthermore, should this work conclude that strap integrity is the limiting factor in the lifetime of a given N95 mask, understanding these underlying failure mechanisms will provide insight into the development of feasible material alternatives or modifications that can be made to extend overall mask lifetime.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.