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This is a major limitation on "muscle wires" when using them for products that require a high number of cycles of greater than 100k.
The attached CNN video is fascinating. It seems a shame that the research seemingly abated. Can anyone else speak to whether more work is being done into the metal or its applications?
I recently went to a talk at my university on microcombusters but the professor (I cant remember his name off the top of my head) was also working on small insect like drones. There were videos of nitonol powered beetle crawling and a non flying prototype of a bee drone with nitinol wing flappers. Rather cool but he said they are incredibly inefficient compared to traditional electric motors.
Those work by using electrical resistance to heat a sample, which moves, and then cools off and can be moved back again, such as by a spring. Turning high-grade electrical energy to low-grade heat, thence to motion, wastes most of it (probably ~70%) vs. a magnetic motor that wastes normally less than 10%.
But nitinol can extract high-grade mechanical energy (kinetic energy of motion, or potential spring tension) from existing low-grade heat by conducting the heat from a higher temperature source to a lower temperature sink. I don't know why the other commenter claimed they wear out; the reported experience from labs was that after 20M cycles they were (a little) stronger than they began.
One problem with Nitinol is that it has a limited number of cycles before the material becomes weak and then breaks or no longer returns to its proper state. This is a major limitation on "muscle wires" when using them for products that require a high number of cycles of greater than 100k.
I balked at first glance because "free energy," but here we have a unique method for turning thermal into kinetic energy. Slightly outside the bounding box of this energy system, of course, lies the expending of more energy than what's produced to keep the hot water hot and the cold water cold. But using natural low-grade temperature differentials as the author suggests, what might this arrangement achieve that a Sti…
Earlier quoted context omitted.
I recently went to a talk at my university on microcombusters but the professor (I cant remember his name off the top of my head) was also working on small insect like drones. There were videos of nitonol powered beetle crawling and a non flying prototype of a bee drone with nitinol wing flappers. Rather cool but he said they are incredibly inefficient compared to traditional electric motors.
You can make very tiny motors with nitinol, but it is a real waste of the capability of the material. Those work by using electrical resistance to heat a sample, which moves, and then cools off and can be moved back again, such as by a spring. Turning high-grade electrical energy to low-grade heat, thence to motion, wastes most of it (probably ~70%) vs. a magnetic motor that wastes normally less than 10%. But nitinol…
One problem with Nitinol is that it has a limited number of cycles before the material becomes weak and then breaks or no longer returns to its proper state. This is a major limitation on "muscle wires" when using them for products that require a high number of cycles of greater than 100k.
Where are you getting this? The credible sources I find say they improve with use.
So if you had a mechanical device that operated at 1HZ, it would fail in less than a year.
https://www.nitinol.com/wp-content/uploads/2011/05/Pelton-20...
I balked at first glance because "free energy," but here we have a unique method for turning thermal into kinetic energy. Slightly outside the bounding box of this energy system, of course, lies the expending of more energy than what's produced to keep the hot water hot and the cold water cold. But using natural low-grade temperature differentials as the author suggests, what might this arrangement achieve that a Sti…
We already have this unique method via Nichrome wire. You can see a really neat application of this in a common toaster here: https://www.youtube.com/watch?v=1OfxlSG6q5Y
Any advice on where to get started on nitinol alloys/engines as a layman tinkerer?