#HTE

How Would People React to Having an Additional Thumb?

While going for her Masters at the Royal College of Arts’ Design Products Programme, Danielle Clode devised an interesting project that’s part prosthetic and part conversation starter: The Third Thumb. By 3D printing in disparate materials and rigging up the mechanicals, Clode created a workable, functional limb extension. 

Here’s how her test subjects reacted to it:

Why she did it:

The Third Thumb investigates the relationship between the body and prosthetic technology in new ways. It is part tool, part experience, and part self-expression; a model by which we better understand human response to artificial extensions. It instigates necessary conversation about the definition of ‘ability’.

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 she did it:

The human thumb has a really dynamic movement, the opposing movements working together make the thumb more functional than a single finger. The Third Thumb replicates these movements by using two motors pulling against the natural tension of a flexible 3d printed material. The motors are controlled by two pressure sensors retrofitted into your shoes, under your toes, and communicate to the thumb via Bluetooth connection. The foot control is inspired by products that help to develop the already strong connection between our hands and our feet. For example driving a car, using a sewing machine, or playing a piano.

What it’s made of:

The base working model design of the Third Thumb is made of three main 3d printed parts. The structural cover for the hand and wrist cover for the motors are both 3d printed in the rigid, smooth formlabs grey resin. The main part, the thumb is live-hinge based design, 3d printed out of the tough, 85a shore flexible filament, Ninjaflex. These parts are all connected via a bowden cable system, similar to a bike brake, made of teflon tubing and wire. 3d printing is perfect medium for this project, as it enables quick prototyping, customised designs for various hand sizes and one-off production.

“Aesthetic Territories”

The working prototype is the base model for the design. The project includes two potential aesthetic territories for the Third Thumb. The first is a tool aesthetic with an electronic element, inspired visually by a cross between a watch, a power tool and a fitness tracker. As a functional piece, this Tool Third Thumb would be 3d printed in a multi-shore 3d print, ranging from a soft flexible print of the thumb, to a more rigid shore towards structural points needed on the hand. The second aesthetic exploration is a kinetic jewellery Third Thumb inspired by another form of body modification expression, tattoo. The design is created with form lines from the working model, and is functional, but purely aesthetic. It is a mix of two types of 3d printed materials, the main body structure is a rigid 3d printed black formlabs resin, and the connecting lines on the joins are flexible, recreating the movement of the thumb.

The Takeaway

The Third Thumb aims to challenge the perception of prosthetics. By extending the body I see it creating a similar trajectory for prosthetics as glasses or plastic surgery. Creating a shift from medical device to positive body image statement. Success is widespread social engagement with The Third Thumb, from a jewellery designer, to a falcon handler, to a tattoo artist, to a toddler, the more people who experience it, the better, framing it in different functions and aesthetics. The current Third Thumb design as a starting base for a lot of future adaption of aesthetic. 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.

The Third Thumb won the RCA’s Helen Hamlyn Award for Creativity. Congratulations Ms. Clode!