Week 6/7: Some Results!

Hello everyone, and welcome back! Last week was Spring Break, hence, no post, so I combined the two weeks into this blog post. This week, I continued working on testing my hydration-monitoring prototype by improving my gelatin hydrogel setup. I made a new “normal” gelatin sample using a ratio of 1 tablespoon of gelatin to 1/4 cup of water, which serves as my baseline for comparison. To better simulate how moisture might be released from skin, I covered the gelatin with Saran Wrap and poked small holes into it, allowing limited evaporation while still keeping the system somewhat controlled. After preparing the sample, I placed my sensors into position and took an initial reading of both temperature and humidity.

Instead of just taking quick measurements, I let the gelatin sit and recorded daily readings over the course of a week. My goal was to see if gradual changes in hydration would show up in the data over time. However, the results were not what I expected. The temperature readings stayed around room temperature, although there was a slight drop during the week because it got colder over spring break. More importantly, the humidity levels remained almost constant throughout the entire testing period. This was likely because the Saran Wrap covering limited how much moisture could escape, preventing any noticeable decrease in humidity.

Even though the results didn’t show dehydration trends, I was still able to make an important improvement to my code. I updated the logic for the DHT22 humidity sensor by adding an upper threshold of 70% humidity. Originally, I only had a lower threshold (40%) to indicate dehydration risk, but I realized that I can look at causes of dehydration, one being excessive sweating (high humidity). After adding this upper threshold, my Arduino was able to classify conditions where humidity was too high as a “mild risk”, which makes the system more realistic and responsive to different scenarios.

For next week, I plan to modify my experiment by removing the Saran Wrap covering entirely. This should allow the gelatin to lose moisture more freely and hopefully cause the humidity readings to drop closer to my lower threshold. I also want to begin doing more self-testing to compare how real skin behaves versus the gelatin model. Overall, even though this week didn’t produce the results I was hoping for, it helped me refine both my testing setup and my code, bringing me one step closer to a more accurate hydration-monitoring system.