Metal interconnection on polymers for steerable microcatheters

Abstract

Currently, minimum invasive surgery is important for patients. Therefore catheter system is generally used for endovascular surgery which is less dangerous than surgical operation. Especially, microcatheter is used for stroke surgery. But, microcatheter surgery has several limits. These limits include small size, not steering, manual controlling. Thus, actuator and controller are studied for improving these limits. In this study, metal interconnection between actuator and controller is developed. Stable interconnection is also important. General metal interconnection methods have several limits such as small scale, flat or hard substrate, high temperature heating and cost. In case of microcatheter, there are some challenges on manufacturing including biocompatible, heating problem, curved surface, micro scale. Thus, gold micro wire and UV adhesive were used to satisfy above challenges. For steering 2-D plane, 4 independent electrical channels are needed. Therefore, 4 gold micro wires were attached on microcatheter. After manufacturing, mechanical reliability test was performed. Gold wire`s tensile modulus was ~60 GPa and elongation was ~5 %. Also, microcatheter assembly`s bending stiffness and delamination strain were measured. Bending stiffness was increased ~38% compared to the bare microcatheter. Delamination strain was over 5 % at static bending. In addition, gold wire and microcatheter assembly`s fatigue test were performed. Finally, microcatheter assembly`s bending motion was analyzed by simulation (ABAQUS).