After losing four fingers on his left hand, and fabricator Ian Davis learned his insurance wouldn’t cover the cost of a prosthetic. “To be eligible for a prosthetic you would have to lose your palm as well,” he was told, according to Interesting Engineering.
Davis then embarked on a mission to create his own prosthetic hand, adding functionality absent in off-the-shelf models. As one example, he’s designed the fingers to be able to splay:
Davis has been documenting his progress on both his Instagram and YouTube channels. And intriguingly, he’s now started experimenting with self-made power tool prosthetics that eliminate the “middleman” of fingers, and instead interface directly:
Davis’ company is called Acme Works Fabrication, and in addition to following his social media feeds linked above, you can learn details of his builds on this Reddit thread.
https://www.core77.com/posts/102514/After-Insurance-Wont-Cover-It-Mechanical-Engineer-Builds-Own-Prosthetic-Hand-and-an-Impact-Driver-Attachment