The Universal Socket Prosthetic tackles the challenge of limb differences from a completely new angle. We aim to reframe prosthetic design, allowing anyone to create a customized prosthetic system that they can adapt and use over long periods of time. Rather than attempting to design a “jack-of-all-trades” arm, our socket system uses varying custom attachments to accomplish a wide range of tasks. It consists of a mesh, sandwich interface with the residual limb, combined with a hexagonal socket that accepts a corresponding shaft on attachments. Users can resize the mesh to fit different arms, and the attachment system allows for easy development of new components with simple CAD skills.
The system is particularly well suited for children: its affordability distinguishes it from most prosthetics, which are complex and costly to make yet need to be replaced frequently as children grow. Furthermore, its ease of creation and editing allows for active use as kids grow, break things, and explore new activities. Each component of the design is large, colorful, and does not require high dexterity, so that even children younger than five can properly operate it. Our research and interviews with parents found that children did not care if the hand is skin-colored, or about the precision of the engineering. They want something that looks fun, is easy to use, and keeps them from getting left out of the activities they enjoy. Based on these insights, hobbies and sports have become a focal point of our work.
Our prosthetic can attach to anything the user wants by adding a simple 3D-printed hexagon to any object, from a baseball bat to a painter’s palette. The specific functionalities that this system enables are key to its value: while more complex prosthetics are generally designed to carry out a variety of tasks, they often do not perform any one task exceptionally well. By distributing high-level functions across a modular system, our design aims to equip prosthetic users with a toolkit for effectively and enjoyably participating in a wide range of activities. While at least one other company has pursued a similar approach to prosthetic design, specializing in sports and musical attachments, these products are very complex (which would make it difficult for kids to use) and expensive to buy and replace. Our design aims to lower these barriers, bringing high-performing prosthetics to a broader audience.
The Universal Socket Prosthetic has enormous potential for accessible impact, and we hope that a diverse community will join us in continuing to build on this concept — allowing anyone with a limb difference to explore new hobbies with ease and flexibility.
Overview and Background
The project was created as part of a mechanical engineering and bioengineering course, Designing for the Human Body, taught by Grace O’Connell and held at the Jacobs Institute for Design Innovation at UC Berkeley.
The Universal Socket Prosthetic was developed in conjunction with the nonprofit Claws from Carter. We worked with the organization’s founder, Michael Campos, whose son Carter was born with a limb difference. The direct impact that our idea could have on Carter’s life has driven our passion throughout the project process. It was important to make the product not only functional and cost-effective, but also fun to use — at the end of the day, it did not matter how good our dimensioning and tolerancing was if Carter did not love using our design.
As we faced time and budget constraints in our design process, we also employed lightweight methods of testing our design: for example, to optimize the weight reduction with structural strength without wasting days on multiple 3D prints, we first laser cut designs out of paper as structural analogues. While this method was far from perfect, ultimately our rapid-prototyping approach, paired with a close collaboration with end-users, led to a functional and appealing prototype. We believe this testing method can be used in future design processes that are constrained on time and budget, reducing barriers to prosthetic design.
A distinguishing characteristic of our design is its robustness, and how well it handles “noise,” by which we mean any deviation from the norm in the building process or usage. The design can be successfully produced with a wide range of 3D printers, including fairly low-cost printers. Similarly, pieces can be made too big or too small by quite a wide margin and still function well, while the flexibility of the arm interface allows it to fit snugly on a variety of arm sizes. These factors lie at the core of the Universal Socket Prosthetic’s value: it represents a truly flexible, accessible prosthetic design system for anyone in the world.