What are the most popular applications of Nitinol(SMA)?

What are the most popular applications of Nitinol(SMA)? Nitinol shape memory alloys have been widely used: A.Industrial B.Aerospace C.Medical D.Toys E.Training Aids F.Automatic control science and other several of enterprises at home and abroad.However, since the increasing performance requirements and size restrictions, here we need to develop high stiffness nickle and titanium shape memory alloys.