Design Step 5 - 8

Our Goal

The goal of Capstone Step 4 was to finalize the technical specifications of our wireless heating pad. We wanted to reduce uncertainties in our design, focusing especially on heat distribution and battery performance. This step involved testing different battery types, analyzing power delivery and heat output, and creating detailed CAD drawings. We also completed a life cycle analysis to better understand the environmental impact of our product from start to finish.

Project Comfort Website: https://qudean.wixsite.com/project-comfort

Content

Battery Efficiency TestWe tested three battery types (3.7V Li-ion, 9V, and 7.4V rechargeable) in three separate trials each. We recorded temperature data each minute until the battery ran out. The 7.4V battery gave the best results for sustained and effective heating.

Heat Distribution Test
What We Did: We placed thermistors at five locations on the pad (corners and center), powered it with the selected battery, and recorded temperatures over a 10-minute period. We ran this experiment three times. Results showed the center had the highest heat, and we now plan to tweak our carbon fiber layout for better evenness.

CAD Models
We used Onshape to create 3D technical drawings of our heating pad prototype. The models show where the nichrome wire, battery, insulating layer, and switch are located. These drawings help ensure our design is buildable and manufacturable.

Life Cycle Assessment
We evaluated how our heating pad affects the environment from material sourcing to disposal. We considered battery reusability, material waste, and electricity usage. This helped us think beyond the prototype and into real-world impact.

Reflection

Throughout this phase, we demonstrated strong collaboration and communication. We were consistent with updates and check-ins, and each group member contributed to prototyping, testing, and modeling. We also maintained open communication with our mentor, helping us stay aligned with our goals. Our testing of multiple battery types showed our curiosity and willingness to improve based on evidence.

However, one area for growth is conscientious learning. At times, we found ourselves rushing or working close to deadlines, which impacted our time management. We could improve by breaking tasks into smaller chunks and setting clearer internal deadlines. Additionally, we want to challenge ourselves more with the prototype itself by refining features like heat consistency and the structure of the pad to better suit our users’ needs.