Give three thumbs up with this robotic extra finger

Prosthesis is nothing new but the 3D printing and robotics have made it both more accessible as well as more advanced. But what if you don't have any missing limb or body part? What if you just wanted to add one more? That's the very question that Dani Clode from UK's Royal College of Art is trying to answer. And her first answer comes in the form of a thumb that you can attach to your hand and control with your feet.

Clode challenges the common conception, or misconception, of what prosthesis is. It is commonly associated with products aimed at replacing lost or missing body parts. The origin of the word, however, is to add, not replace. And so Clode designed a prosthetic thumb to give you a third one, not replace either of your existing two.

Unsurprisingly, much of this Third Thumb is 3D printed. The thumb itself is made from Ninjaflex, a flexible plastic filament. Two motors located on a wrist strap pull the digits in different direction and bend them at the knuckles. Or hinges rather.

The unique part of the Third Thumb, however, is in the way it is controlled. It doesn't make use of brainwaves or muscle contractions in your hand or arm. Instead, it is controlled by the wearer's foot, using pressure sensors hidden inside their shoe. This rather odd mechanism is by design, meant to demonstrate the connection between our hands and our feet.

What would you use an extra thumb for? Maybe for riffing a guitar, getting a better grip on things, or counting to eleven. While it can probably be turned into an actual useful product, Clode might be more interested in challenging conventions and probably giving rise to an equally loaded term: human augmentation.