The successful placing of catheter-based medical devices such as angioplasty, stent placements, and thrombectomy need variable stiffness combined with as much flexibility as possible. Those are two opposing needs, but Solvay has achieved this with its Radel polyphenylsulfone (PPSU). The material is being used by RiverTech Medical in one layer of that company's precision micro-tubing with variable flexibility for catheter-based medical devices. This microtubing, shown here, offers two to three different stiffnesses and flexibilities in a single component, Maria Gallahue-Worl, global business manager for healthcare in Solvay's specialty polymers division, told Design News.
RiverTech Medical made the micro-tubing with multiple layers of different polymers, plus a layer of woven wire material for reinforcing tubing walls. Radel PPSU provides strength and stiffness as the top layer, which is 0.002 inch (0.00508 cm) thick. The polymer's strength and melt processability are comparable to those of competitive materials like polyimide, and it can endure more than 1,000 cycles of steam sterilization without a significant loss of properties.