If the X-Finger looks like a prop from The Terminator , relax. It isn’t out to kill you, and it isn’t robotic. In fact, it’s a mechanical prosthetic finger so effective it provides articulation as fast and flexible as the real thing.

This article has been reproduced in a new format and may be missing content or contain faulty links. Contact wiredlabs@wired.com to report an issue.

Invented by Dan Didrick of Naples, Florida, the device has no batteries, electronics, servos or actuators. Instead, each digit incorporates a simple mechanism which, when pushed by the surviving part of the wearer’s finger, curls a set of artificial phalanges.

“Having a body-powered device leaves little room for mechanical failure,” Didrick said, adding that there aren’t any robotic medical alternatives. “Many people assumed a device such as mine already existed.”

In practice, however, robotic fingers are always attached to robotic hands and arms. Losing an entire limb, however unpleasant, allows the prosthetic manufacturer more room to conceal complicated electronics.

About one in 150 people have lost a digit to war, misadventure or misfortune.

Made of steel and blue plastic, Didrick’s X-Finger allows for a surprising degree of dexterity: Enough to grip (and swing) a golf club, operate a keyboard or even play musical instruments.

When the wearer bends the remaining portion of his or her finger, the tight fit causes it to depress a lever on the X-Finger, articulating the device in proportion to the pressure exerted.

The precision mechanism guides the digit’s movements to match those of adjacent fingers, creating an uncannily realistic prosthesis where it counts most: mobility, power and accuracy.

In May, Didrick was awarded second prize in the History Channel’s Modern Marvels Invent Now Challenge, beating thousands of other entries to claim a $5,000 award.

The X-Finger, which currently costs thousands of dollars per digit, might seem expensive to prospective buyers. But it’s not a get-rich-quick scheme for its inventor: Didrick, 37, sold his house, his Porsche and many of his personal possessions to help fund development, and he draws only a modest salary from sales of his invention.

“We only receive a fraction of the overall costs ourselves,” Didrick said. “Also, many people would be surprised to learn that a cosmetic silicone artificial finger, offering only passive function, with no mechanical structure, can cost $5,500 from an anaplastologist.”

Didrick’s X-Finger works much like a real finger, with its flexing motion actuated by movements in the surviving parts of the wearer’s finger and hand.

Manufacturing is currently taken care of by a firm in California, but it is able to make only a few fingers a week. Investment will expedite production, Didrick hopes.

Didrick started out as a maker of realistic monster masks, and eventually moved to Japan, where he planned to work at the movies. Though Didrick didn’t make a career articulating Gojira’s mighty digits, he noticed that many workers in heavily industrialized Kawasaki were missing their own. After crafting a silicone replacement for a stranger at a party, word spread and he was soon supplying artificial fingers to inattentive machine operators.

Returning to America, he found a patient who needed a more versatile facsimile, leading him to study anatomy and invest in CAD software. Six years later, the resulting invention is a commercial reality.

The finger, however, is only the beginning. Didrick is already working on an entire hand articulated in similar fashion using the wrist, and has been approached to craft toes using the same principle.

“Our new approach to prosthetic technology will have a significant impact, not only on the thousands of lives it will change, but also to spark the ingenuity of our youth to develop new technologies for the future.”