Nitinol Actuating Fibers---on Materials, Processing and Miscellaneous

Due to high-cyclic and miniature requirements for toys, white household appliances, or medical devices, there is a tremendous trend on demanding thinner Nitinol actuating elements, especially at the level of no more than 100 micrometer in diameter, and thus called Nitinol actuating fiber.  In addition, owing to the fact that the actuating elements work in the temperature range from room temperatures to elevated temperatures, thus the corresponding modulus at the two phases are significantly different, e.g., extremely plastic-soft at room temperatures and very high upper plateau superelastic at elevated temperatures.  Thus the very delicate material composition selection, special care to processing of the actuating fibers, as well as related testing and actuating performance evaluating for such fibers, are essentially different from the conventional ways in treating thick diameter superelastic Nitinol materials. The paper presented here mainly focuses on the above aspects, and also deals with some other miscellaneous, including potential briefing on its applications.