Making Connections: Modular 3D Printing for Designing Assistive Attachments to Prosthetic Devices
Megan Kelly Hofmann · 2015 · ASSETS '15: Proceedings of the 17th International ACM SIGACCESS Conference on Computers & Accessibility · doi:10.1145/2700648.2811323
Summary
This doctoral consortium abstract presents a modular design methodology for creating affordable, customized 3D-printed assistive attachments for prosthetic limbs. The approach addresses a key limitation of current assistive technology: highly customized devices are expensive to engineer and produce, yet necessary for many specialized tasks. The methodology breaks prosthetic attachments into three interchangeable components: the prosthetic itself (a wrist or arm piece customized to the user's residual limb), the assistive device (task-specific tools like grips or holders), and an attachment interface connecting them via a lock-and-key mechanism. This separation allows designers to iterate on each component independently, test multiple configurations rapidly, and accommodate user growth or changing needs without redesigning the entire system. A key innovation is the testing interface using 3D-printed Lego-compatible studs, enabling quick repositioning and configuration testing before committing to a final design. The modular approach also means that assistive devices designed for one user can be shared online (via platforms like Thingiverse) and adapted by others with different prosthetics.
Key findings
Two case studies demonstrate the methodology's practical application. The first involved a 9-year-old boy with a congenital below-elbow amputation who wanted to play the cello. The team sourced an adaptive violin bow holder from Thingiverse, modified it for cello use, and used the Lego-stud testing interface to find optimal positioning. Multiple prosthetic gauntlet sizes could be printed without redesigning the bow holder—important for a growing child. The second case involved a 27-year-old woman with a congenital below-elbow amputation who uses a hand-cycle for recreation. Since she cannot easily grip the left handle, most cycling effort falls on her dominant arm, causing strain. Here, the methodology adapted to a non-printable device (the hand-cycle itself) by designing an attachment interface using Velcro for position testing, demonstrating the approach's flexibility beyond purely 3D-printed solutions. Both cases highlight how modularity reduces iteration time, enables component reuse, and transforms expensive custom engineering into accessible maker-style collaboration between users and designers.
Relevance
This research has significant implications for democratizing assistive technology. By applying modular design principles to 3D printing, the methodology lowers barriers to creating customized prosthetic attachments—making them accessible to individuals, schools, and maker communities rather than requiring expensive clinical engineering. The approach aligns with growing interest in personal-scale fabrication and open-source assistive technology communities. For accessibility practitioners, this work demonstrates how participatory design methods can empower prosthetic users to become active collaborators in creating tools for their specific activities, from musical instruments to sports equipment. The limitation of this short paper is its scope—only two case studies with upper-limb amputations. The author notes future work will address more diverse users, tasks, and impairments, as well as automation tools for generating designs. The modularity framework, however, provides a solid foundation for expanding to other domains of assistive device customization.
Tags: 3D printing · prosthetics · assistive technology · rapid prototyping · modular design · upper limb amputation · participatory design