The final design is shown below in Figure 1.a. The device has the screen in the center placed on the top with the rest of the components on the inside. These components include the Arduino Nano, the battery holders and batteries, the linear actuator, and the color sensor. The test strip will be placed inside the drawer and read by the color sensor. As shown in Figure 1.b , the actuator extends to the end of the test strip to allow for color sensing of test strips containing multiple parameters. Moreover, there is a cone encapsulation attached to the color sensor to direct the light of the sensor and only read the color square of interest.
a.
b.
Figure 1: a. The overall design with all components shown. b. A zoomed-in view of the extended linear actuator, color sensor, the cone encapsulation, and the strip in the drawer.
Decision Matrix
| Designs | Screen Placement | Screen Tilt | Strip Placement | Device size | Score |
| 1 | Top (3 points) | Yes (1 point) | Slot(1 point) | Thin (1in)(2 points) | 7 points |
| 2 | Front(2 points) | No (3 points) | Hinges(2 points) | Thick (8in)(2 point) | 9 points |
| 3 | Top(3 points) | No (3 points) | Drawer on the side(3 points) | Thick (8 in)(1 point) | 11 points |