Swab Tensile Testing and Procedures

This tensile test is to mimic the worst-case scenario of the swab being caught on an obstruction when being pulled out of the nasopharyngeal space. It is to determine how much tensile force the swab can withstand without breaking. A variety of different swabs (different materials and different geometries) were tested using the protocol outlined in Section 2 (Tensile Testing Procedure). Not all of the swabs were pre-treated using the Autoclave. For those swabs that were pre-treated using the Autoclave, the tensile tests were performed within 6 hours of completion of the Autoclave pre-treatment, unless otherwise noted. The FormLabs-USF and FormLabs-Northwell were printed at LLNL using FormLabs Surgical Grade V1 Resin on a Form 3B Printer. Results Summary: All FormLabs design and treatment variations (e.g. autoclaving and “aging”) had higher tensile strength compared commercial swabs. Autoclaving degraded the tensile strength. “Aging” after autoclaving improved the tensile strength. “Aging” without autoclaving degraded the tensile strength. No differences were observed in tensile strength with different autoclaving protocols. No significant differences were observed in tensile strength for different batches.