PROMETHUS Arm

As part of CSUN’s Smart Prosthetics team, I led the palm design for a below-the-shoulder prosthetic arm intended to improve usability for transhumeral amputees. The larger system paired foot-based gesture control with haptic feedback, so the palm had to do more than simply move. It had to package the actuation hardware within a hand-sized envelope and still preserve useful finger motion.

My work centered on designing a palm that could house two high-torque servos within each digit without turning the hand into an oversized mechanical block. That problem was mostly about packaging. It forced careful decisions about how much material the structure needed, how the tendons would pass through the palm, and where the design needed to resist deformation once it was printed and assembled.  I used MSLA printing where the design depended on finer internal features, especially around tendon routing and sensor placement. For the front section of the palm, I used TPU on an FDM printer with gyroid infill so that area could deform under contact instead of acting like a rigid shell. That material choice was tied to the way the hand would meet an object and how much compliance the assembly could accept before control degraded.

I also supported other parts of the build as the project moved forward. I assisted with fabrication of the carbon fiber composite shells for the forearm and bicep, with attention to layup sequence and curing so the structure came out sound. I handled the resin parts from slicer setup through wash and UV cure. In the lab, I helped teammates work through CAD issues when the geometry started fighting the process. I also helped with print setup when parts needed different support strategy or orientation. When newer team members needed help with soldering or lab safety, I stepped in there as well.

Full assembly of the PROMETHEUS Arm.