Nitinol in Heat Engines — A Partner Material for LENR?

An interesting video was posted by Jack Cole on the Vortex-l mailing list about a material I had never heard of before – nitinol, a super-elastic alloy of nickel and titanium which, when cold, is easily bendable and quite floppy, but when heated, remembers its original shape and immediately snaps back to its former condition.

The video below was produced by CNN in 1982, where science editor Kevin Sanders visited the Lawrence Berkeley National Laboratory and talked with physicist Edwin McMillan (1951 Nobel prize winner in chemistry for “discoveries in the chemistry of the transuranium elements”) about the singular properties of Nitinol, and looked at the potential of the metal for use in heat engines.

I think the video is very interesting and well produced, and there was considerable discussion at the time among scientific authorities about the possibility of using nitinol to convert heat into mechanical and/or electrical energy, but for some reason the idea seems to have died since the time of this report.

A little reading about the topic reveals that there are challenges involved in the use of nitinol. It is expensive to make, hard to weld, and despite having exceptional durability when flexed, when put under great demand it has been observed to fail due to fatigue.

Still, I found the video fascinating, and wonder why I hadn’t heard about this very interesting metal sooner, and I wonder if there might be applications for it connected with LENR — which of course is a source of heat.

See also Axil’s post here today for other possible applications for nitinol with LENR.

  • Hi all

    You can buy Nitinol including tubes 😉 here:

    Kind Regards walker

  • Gerard McEk

    I guess that the main reason that it is not being used for motion purposes in the kWatt area is that it may be not that efficient, otherwise it would have been done long ago.

    • Hi all

      Actually at low heat it is relatively very efficient.

      Kind Regards walker

    • Omega Z

      Yes, this is old news. I recall when the Navy was making it available for free to anyone who had a viable idea. Did I just give away my age?

      Nitinol can be designed for specific temperature range & can respond very quickly with a lot of psi force. I am somewhat surprised it hasn’t made it into a mainstream product, except, if your product required very much, it is probably cost prohibitive.

      It is complex to manufacture & no one seems to think it will ever become cheap to make. They are working with other metals with memory, but I don’t know what progress they have made.

      I had an innovative idea that didn’t fly.
      An ejection seat activated by the heat of a fart.
      While it did ejected the culprit, the stink stayed behind…

  • Mark

    This nitinol stuff looks pretty cool. It reminds me of that “memory metal” that some of those folks claimed that they got from the alien spacecraft that crashed at Roswell. This nitinol seems to need a good deal of heat before it will spring back into its original position. I wonder if there has been any attempt to find any other metals, perhaps related to nitinol, that will spring back to their original position at room temperature, like the “memory metal” supposedly does.

    • Omega Z

      “claimed that they got from the alien spacecraft”
      NRL has denied they reverse engineered this from the Roswell crash.
      Just before they started issuing it for experimental purposes.
      Yes, there is ongoing research into other memory metals.

  • Thomas Kaminski

    I believe that the nitinol fatigue was an issue for longevity. Actually, a more promising material is simple nylon fishing line. This is a link to the artificial muscle research on nylon thermal actuators:

    As with all polymers, it must be used below its melting point. With regeneration, it can be treated as a working “fluid” in heat engines similar to Stirling engines. Many articles in the past talk about “rubber-band” heat engines.

    The key to efficient operation is a to find a material that has stress change under temperature change and a material that can be formed into a structure with good heat transfer.