Meta Mecha: A Personalized and Medically Compliant Prosthetic Socket Liner

Combining Metamaterial, Computational Design, and 3D Printing

The future trend of computational design draws our attention to programmable matter and metamaterial. Xuerong Cai, the designer behind Meta Mecha, was surprised to find the potential of metamaterial to empower design with material science. Motivated by this discovery, Cai and the design team proposed the application of metamaterial in the prosthetic field, offering both customized and medically compliant service.

What sets Meta Mecha apart is its use of 3D printable mechanical metamaterials as the prosthetic liner. This innovation allows for the customization of mechanical surfaces for different amputees, according to their personalized medical requirements. The prosthetic liner is designed to be pressure-sensitive and color-changing, providing visualization of unsuitability and drawing attention to potential issues. Additionally, the liner can be easily replaced to support the deformation process of the residual limb, allowing users to update their mechanical surface inside the prosthetic in a simple and economical way.

The realization of Meta Mecha relies on advanced technologies such as 3D printing and generative design. The mechanical metamaterial prosthetic liner is 3D printed with industrial-quality 3D printers using elastic TPU. This complex 3D shape would be impossible to manufacture without additive manufacturing technology. Before the design process, 3D scanning and pressure sensor equipment are used to acquire the shape and mechanical requirements of amputees. The generative design approach, using tools like Grasshopper, is then employed to generate a design that meets the customized requirements of each individual.

Meta Mecha's interaction with users begins with a 3D scanning of their residual limb and collecting pressure distribution data while walking in a common socket. Based on this data and the user's medical requirements, a 3D model of the metamaterial prosthetic liner is generated. After 3D printing, the liner is assembled with other parts of the prosthesis and delivered to the user. The prosthetic liner adjusts the best pressure level for the user and warns them when pressure exceeds tolerance limits through color change. This visual cue allows the user to understand when it's time to replace the liner to fit their residual limb deformation.

The Meta Mecha project started in October 2021 in Shanghai and the first prototype was exhibited in D&I Shanghai in December 2021. An educational exhibition based on the project was shown in Shanghai Dyson Ideation Lab from February. Extensive research on mechanical metamaterials, medical requirements for prosthetics, and computational design was conducted to ensure the feasibility and effectiveness of the design. The design team faced challenges in understanding the logic and process of editing mechanical metamaterials, but with the help of experts and experimentation, they successfully arranged the structure unit on the prosthetic liner using Grasshopper and plugins. Finding an industrial 3D printing laboratory capable of printing the complex structure of metamaterial with TPU was another obstacle that the team overcame.

Meta Mecha has been recognized for its innovation and practicality, receiving the Iron A' Design Award in Cybernetics, Prosthesis, and Implant Design in 2023. This award is given to well-designed, practical, and innovative creations that meet professional and industrial requirements. Meta Mecha's integration of industry best practices, competent technical characteristics, and contribution to a better world have earned it this prestigious accolade.

Meta Mecha represents a significant advancement in the prosthetic field, combining metamaterial, computational design, and 3D printing to provide personalized and medically compliant solutions. With its customizable mechanical surfaces and pressure-sensitive features, Meta Mecha offers users a comfortable and functional prosthetic experience. As technology continues to evolve, we can expect to see more groundbreaking designs like Meta Mecha that push the boundaries of what is possible in the world of prosthetics.