Effect of Electrical Current on Nitinol Medical Staples Shape Memory

Medical staples are one of the nitinol shape memory alloys applications which their pedicles have to be bent for suitable function with an appropriate angle at a specified temperature .It is achievable by shape memory effect. For this purpose, samples of nitinol super elastic alloys were bent in a steel mold with different angles & formed orthopedic staples. Then shape memory effect was induced in all samples under aging process. In this research effect of heat generated in the shape memory alloys specimens due to electrical current was investigated. Phase transformation temperatures of samples were measured by differential scanning calorimetry (DSC) technique. Results showed that smaller bending angel results in lower amount and duration of current for shape recovery. Strain increased in them in the same amount of current. Results of this study can improve manufacturing of NiTi medical staples.