Phase 4

Phase 4 was primarily focused on refining the team's fabrication plans for the ThermoElectric Generator (TEG). Moving into this Phase, the group struggled with leg fabrication as it was extremely difficult to remain consistent with the semi-conductor powders. The original model of the group's TEG included 16 TE legs, but the group reduced it to 2 to conserve materials and to fit in the micro oven available.

Based upon feedback from the panel and the results of the alpha prototype in Phase 3, the group developed a refinement plan that was implemented throughout Phase 4. In order to make the fabrication process more consistent, an auto pipette and a vacuum were used in the manufacturing of the pastes. The group had one successful pair of TE legs that they continued the fabrication procedure by working on the copper plate and assembly procedures to connect the legs together and generate a voltage.

Due to the amount of variables in the fabrication process and the limited technology provided at Stevens, the group also utilized Phase 4 to create a Plan B. They purchased a pre-manufactured 30 mm TEG and an Arduino board to work on the software subsystem to test and evaluate the capabilities of the subsystem. The group was able to test the pre-manufactured TEG using a hot plate to find the voltage output over time as well as the voltage output versus the temperature differential. This led to the conclusion to pursue the pre-manufactured TEG, shown, for further test and fabrication processes.

Using this pre-manufactured TEG and a hot plate, the group was able to get data on Voltage Output over Time as well as Voltage Output versus Temperature Differential. This allowed the group to get a better idea of how accurate the TEG was in converting a temperature differential into a voltage output.

The group also worked on the software code for the mobile application in this phase. The primary use of this code is for the application to be able to alert the user of potential infection. A snippet of the code is shown below.

Some primary dates for this phase included:

2/25/20 - Phase 4 Presentation

3/2/20 - Phase 4 Report due

Moving into Phase 5, the team developed a Beta Prototype Plan. The first part of their plan was to purchase a second 30 mm TEG. The team also plans to perform more experimentation such as rerunning the temperature over time test to determine the amount of time that it takes for the TEG to reach a steady state output. The group also plans to begin developing the mobile application's user interface.