For someone missing their leg above the knee, simple tasks like transitioning from sitting to standing or walking up stairs can become almost impossible. This is due to the fact that without a knee, there is no way for the leg to add energy to a person’s stride during these actions which severely impairs their mobility.

Active knee prosthetics (i.e., prosthetics with a powered knee joint) can solve this problem but developing hardware and software to accomplish this is challenging. That is why I helped the Utah Bionic Engineering Lab work on an open-source powered-knee  prosthetic that used off-the-shelf parts from a Makita drill and a 3D printed chassis.

This leg can be used by teams around the world to design and test different control strategies. My primary responsibility on this project was the design of the electrical system, including hacking the drill motors speed controller so that the motor could be controlled by a microcontroller instead of the drill trigger.

To see a current version of this project check out: U-Build Bionic Knee – Open Source Leg (utah.edu)