Pedal-power mobile phone charger

Frequent power cuts at the University of Douala regularly left students unable to charge their phones — part of a wider reality of unreliable electricity across Cameroon. As project leader I set a team of three at HTTTC a hard goal: design and build a human-powered charger in three weeks for the Science & Engineering Festival, on a tight budget, with no prior weldment or FEA experience, and comfortable for users from the 5th to the 95th percentile.

We worked to Design-for-Manufacturing and an Empathize–Define–Ideate–Prototype–Test loop; I taught myself advanced SolidWorks weldment and FEA in a week to hold the deadline. Most of the effort went into the frame — a double-groove pulley transmission and all the electronics packaged inside the structure. When FEA exposed stress concentrations at critical joints above 800 N, I added strategic gusset reinforcements against fatigue, and chose hollow steel tubing for its strength-to-weight ratio.

A working prototype presented at the HTTTC Festival, proving human-powered charging as a viable answer for energy-scarce settings. The simulation-driven approach caught structural weaknesses before fabrication and cut costly physical iterations. It's also where a principle stuck: designing for anthropometric diversity isn't a constraint — it's the measure of a design's real-world value.