I guess, in a nutshell, they attach a small amount of muscle to the nerve that controls something that's going to be cut off. And they anchor that muscle on both ends. So that contracting and relaxing it provides a real-world force feedback loop. Really clever.
https://videos-fms.jwpsrv.com/0_6146535c_0xe8e28ca538bc35a69...
And this article does a better job of explaining the surgery: https://bionicsforeveryone.com/agonist-antagonist-myoneural-...
I guess, in a nutshell, they attach a small amount of muscle to the nerve that controls something that's going to be cut off. And they anchor that muscle on both ends. So that contracting and relaxing it provides a real-world force feedback loop. Really clever.