The Energy-Harvesting Door Opener is a team project for a senior mechanical design course. We sought to create a door opener that would charge itself with human power from normal opening and release that power to open automatically. Such an opener could be farther away from grid access. Other goals included Americans with Disabilities Act compliance, ease of installation and use, and minimal size and weight. Our team split up into two groups, one designing a traditional upper-door linkage system, and the other designing a novel wheel-based system. I worked on the latter project with one other student.

As we could find no evidence of a wheel-based door opener existing, we designed everything from scratch. The main concerns were: choosing the correct type of return spring, designing an adjustable suspension system to ensure wheel-to-floor friction, specifying and packaging the drive chain, and attaching to the door.

The device works as such: when the user opens the door, the wheel turns a set of gears, which backdrives a small motor to charge a battery pack. When the user releases, a spring returns the wheel to the original position. To open automatically, the motor runs this process instead.