Dani Clode is a grad student at London’s Royal College of Art (RCA) and her latest creation is something called The Third Thumb: a 3D-printed prosthetic that does exactly what its name suggests. “The origin of the word 'prosthesis' meant 'to add, put on to,’ so not to fix or replace, but to extend,” Clode told Dezeen. “The Third Thumb is inspired by this word origin, exploring human augmentation and aiming to reframe prosthetics as extensions of the body.”

It’s absolutely unnecessary stuff, and I love it.

The thumb straps on to the side of your hand, and connects to a bracelet containing wires and servos. The wearer controls it using pressure sensors that sit under the soles of their feet. If they press down with one foot the thumb will make a grasping movement, with these instructions sent to the wrist unit via Bluetooth. It sounds a bit fiddly, but Clode says people pick it up pretty quickly. It’s no more complex than, say, steering a car and operating the brake and accelerator at the same time.

It’s just a prototype, but Clode says the aim is reimagine what we think of as a prosthetic — something that adds capabilities, rather than just replacing those lost.

Just imagine: it’s the future sometime. You’re doing business stuff, and you reach out to shake somebody’s hand. You grasp it, firm and unwavering. Slightly too firm in fact. The other person looks down. You’ve got a dang extra thumb, tapping their hand in a confident but businesslike way. Guess who just won that big contract? That’s right, you did. And you can thank your third thumb.