“The value of the Third Thumb is to create a catalyst for society to consider human extension, framed in an approachable, accessible design. It is a tool, an experience, and a form of self-expression. When we start to extend our abilities, and when we reframe prosthetics as extensions, then we start to shift the focus from ‘fixing disability, to extending ability.” -Danielle Clode
Royal College of Art (RCA) graduate student Danielle Clode envisions a future in which we harness technology to augment our humanity. She is intrigued by the idea that people could become even more powerful through augmentation. This interest of hers lead to the creation of a controllable Third Thumb that enables the wearer to extend their natural abilities. She designed the Third Thumb to push us to consider what “optimal” human functioning really is.
Clode’s fascination with prosthetics stemmed from the interaction between people and products. “When you use a pen to write, after a while you don’t feel your hands on the pen anymore – you feel the tip of the pen on the paper,” she said in an interview. “The more research I did on human extensions, the more I became fascinated with prosthetics. I wanted to understand the connection that develops between the wearer and the limb – some wearers feel it is part of them, some name it, and others only see it as a tool.”
In regard to the Third Thumb specifically, a couple of things greatly influenced and inspired her concept for the project. One was something said by biomechatronics mastermind Hugh Herr:
”We the people need not accept our limitations, but can transcend disability through technological innovation.”
The second thing was the origin of the word prosthesis. Clode says:
“The origin of the word ‘prosthesis’ meant ‘to add, put onto’, so not to fix or replace, but to extend. The Third Thumb is inspired by this word origin, exploring human augmentation and aiming to reframe prosthetics as extensions of the body.”
How does it work and what is it made of?
The device is a foot-controlled 3D-printed thumb. It attaches to the wearer’s hand by a watch-like wristband. The motors are driven by two pressure sensors located in the shoes beneath the wearer’s big toes. Clode chose this method of control between the hands and feet since it is a combination people are already familiar with. For example, when driving a car, operating a sewing machine or playing the piano.
The sensors are wireless and communicate with the thumbs motor via Bluetooth. They are responsive to varying amounts of pressure as well as speed. Each foot controls a specific type of movement (range of motion). One pressure sensor controls the flexion and extension of the thumb, while the other controls adduction and abduction.
The hinged-based design of the finger itself is made up of three main parts all printed in one piece. The material used is an agile yet robust, strong type of printing filament called (85A shore flexible filament) Ninjaflex. All the parts (motor to wristband through the finger to tip) are connected via a Bowden cable system made of Teflon tubing and wire much like the break on a bike.
Though the appendage may seem unnecessary, those who’ve tried the Thumb have found it both exciting and unusual. Once they got the hang of it they were able to pick things up, hold things, play the guitar, crack eggs, and squeeze lemons. 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.”
With the introduction of more projects like this comes the potential for a whole new field of elective prosthetics, technology-driven devices designed to upgrade the human body to enhance our abilities. Some find it exciting, others worrisome, but either way, it’s already here.
Do you really need a third thumb? …Well, do people need breast implants? Maybe just watch this video, then decide: