Nitinol Engine

About 1970 there was a first important stage of developing nitinol engines. But since then, 45 years (!), nearly nothing important happened. When I started to discover this phantastic material nitinol I had the illusion, this might be an easy way and i can construct nitinol engines within several days or weeks. But after a short time I began to understand, why this developement stopped for a long time. This material is so strange and in spite of my complexe knowledge in materials and developing things I un