3D-printed robotic thumb changing the game for prosthetics and beyond

Third Thumb 3D-Printed Robotic Thumb
The Third Thumb is a 3D-printed thumb extension for your hand, controlled by your toes.

The concept of human body augmentation has taken a leap forward with the development of a unique 3D-printed robotic thumb designed to function like a real finger. The Third Thumb, created by designer Dani Clode in collaboration with neuroscientist Tamar Makin, has the potential to replace missing parts of the hand, provide extra support for holding objects, and pave the way for future research on human body-part augmentation.

On March 3, 2023, Makin led a talk at the American Association for the Advancement of Science (AAAS) discussing the future of motor augmentation for the body. Advances in technology now enable patients to control bionic arms via direct brain-machine interfaces, bypassing injured spinal cords or missing limbs. There is growing interest in leveraging similar technologies for human motor augmentation, according to the talk description.

The Third Thumb is a product of Clode’s Masters at the Royal College of Art and has won multiple awards. This innovative 3D-printed, robotic thumb offers users extended assistance and explores the relationship between the human body and augmentative and prosthetic technology. Users control the prosthetic finger’s movement by pressing their toes on the floor.

To use the Third Thumb, users wear a motor-connected finger device around their wrists. A microcontroller attached to their arm wirelessly connects the device to the robotic finger and pressure sensors under the big toes. This interconnected system enables the thumb to move and function independently based on the user’s toe control. The 3D-printed finger can thus interpret the user’s desired action through pressure.

Third Thumb 3D-Printed Toe Sensors

Clode emphasizes that the Third Thumb sparks a crucial conversation about the definition of “ability.” She explains that the word “prosthesis” originally meant “to add, put onto,” rather than to fix or replace. Inspired by this origin, the project explores human augmentation and aims to redefine prosthetics as extensions of the body.

Clode and Makin investigate the brain’s adaptability to augmentation by incorporating the concept of neuroplasticity. They seek to understand the resources the brain uses to control a body part that has never been present before and explore how this knowledge can improve the usability and control of future prosthetic and augmentative devices.

Third Thumb 3D-Printed Holding Orange
The Third Thumb can grasp objects like a real finger.

During a recent Royal Society summer science exhibition, Clode and her team allowed participants to try out the extra thumb. Of the 600 people who tried the device, 98% could use the robotic 3D-printed finger within a minute, demonstrating its ease of use and adaptability.

As the research team delves deeper into human augmentation, they raise questions about the physiological and cognitive resources that can be harnessed to control body parts humans have not evolved to manage. These questions were addressed by Makin at her AAAS talk, emphasizing that designers will need to develop novel approaches beyond the traditional assistive technology toolbox to control these new body parts in collaboration with existing biological limbs.

Third Thumb 3D-Printed Holding Cup

Third Thumb 3D-Printed Holding Bottle

The Third Thumb represents a significant step forward in the field of human body augmentation and has the potential to revolutionize the way we view and use prosthetics. By merging cutting-edge technology with a deep understanding of neuroscience, Clode and Makin are transforming the landscape of prosthetic devices and expanding the limits of human ability.

Take a look at the Third Thumb in action in the video below.

Source: Dani Clode, Tamar Makin