EPICS - CASS Secure Lockbox

The CASS Secure Cell Phone Charger was developed through ASU’s Engineering Projects in Community Service program for the Central Arizona Shelter Services. The goal was to create a secure, affordable charging enclosure that would allow shelter residents to leave their phones and valuables charging while completing other essential activities without the risk of theft. The final concept used a transparent PETG enclosure, reinforced metal components, a timed solenoid lock, a reed switch for door detection, protected internal wiring, and an Arduino Nano control system.

As the mechanical design lead, I led a four-member team through stakeholder research, requirements development, concept selection, SOLIDWORKS modeling, fabrication, electronics integration, and validation. I completed more than ten design revisions to improve strength, usability, manufacturability, wiring protection, and lock reliability. I also contributed to material selection, component layout, assembly planning, and testing procedures.

The prototype was evaluated through impact, pull, throw, and static-load testing, including a 200-pound load test. Testing helped identify potential failure points and guided further improvements to the enclosure, hinge, door reinforcement, lock mounting, and internal geometry. The project required balancing security, cost, transparency, accessibility, and ease of maintenance for a high-use shelter environment.

In addition to the physical prototype, our team produced a complete engineering design document covering stakeholder interviews, user needs, design requirements, benchmarking, concept development, decision matrices, risk analysis, manufacturing, testing, and delivery planning. We also created and presented a formal Stage 3 design review summarizing the design process, technical decisions, prototype development, and validation plan.