...researchers developed a way to tame temperamental nerve endings, separate thick nerve bundles into smaller fibers that enable more precise control, and amplify the signals coming through those nerves. The approach involves tiny muscle grafts and machine learning algorithms borrowed from the brain-machine interface field.

“This is the biggest advance in motor control for people with amputations in many years,” said Paul Cederna, who is the Robert Oneal Collegiate Professor of Plastic Surgery at the U-M Medical School, as well as a professor of biomedical engineering.

“We have developed a technique to provide individual finger control of prosthetic devices using the nerves in a patient’s residual limb. With it, we have been able to provide some of the most advanced prosthetic control that the world has seen.”

(Via University of Michigan News.)

SF readers and viewers were aware of these possibilities a generation ago. In Martin Caidin's 1972 novel Cyborg (made into the Six Million Dollar Man television series), Steve Austin has a bionic arm.

"When you think to pick up an object, what happened before with your original arm is repeated. The electrical impulses generated by your brain command everything... The artificial muscles.. which in this case are silastic and vitallium pulleys, then contract, twist, and tighten. You can even sense with your fingertips..."

Update 16-Dec-2022: Take a look at the thought-attuned robotic arm from Bleekman's Planet by Ivar Jorgensen, published by Imagination magazine in 1957:

“It’s thought-attuned. It’s controlled directly from my neural centers, and the linkage isn’t completely smooth yet. It takes time to learn how to use one of those things, and it’s a strain learning. I don’t wear the arm all the time.”
(Read more about the thought-attuned prosthetic arm)

End update. See also:

• Bionic Hand Provides 'Lifelike' Sensations, Like Luke Skywalker's
  A new bionic hand allows the patient to feel "lifelike" sensations when implanted onto the arm.
• The i-limb Ultra Revolution Prosthetic Hand
  The i-limb ultra revolution prosthetic hand has lots of cool features: a powered rotating thumb, biosim mobile control app with instant acess to 24 Quick Grip™ patterns...
• Your Can-Crushing Bionic Hand Is Ready, Steve Austin
  An electromechanical bionic hand with can-crushing grip strength has been developed by a team of researchers from the Tokyo Institute of Technology.
• Bionic Fingertips Would Have Improved Anakin's Experience
  A bionic fingertip has been developed by neuroengineer Silvestro Micera and his team. With it, humans can detect not just pressure, but texture as well.