The Design

These renders detail the final product that I created as Technical Lead for the Lemelson-MIT grant project. Designed to prevent dogs from burning their paws, the COOLAR (patented) monitors ground temperature and alerts the user with their pets location and ground temperature. Using a magnetic slide and lock system, the Coolar interlocks with the base that is attached on the collar, so that the user can take it off and charge it (the biggest problem for any wearable). All of the internal components (Microcontroller, battery, IR Sensor, and GPS) were precisely enclosed by the internal housing, with the addition of a USB-C breakout and power switch for user convenience. I decided to fit the parts together with a friction fit, which was sealed through a plastic welding heat contraction technique. This kept the exterior sleek and undisturbed by screw holes.

This image shows the internals of the Coolar (USPTO 63/509,633). The Coolar uses an arduino microcontroller with two sensors that I soldered: ground temperature sensing using an infrared thermopile and location tracking using GPS. Testing the accuracy of the thermopile, I noticed that it underestimated temperature as height increased. To counteract this, I ran a regression model on the data and developed a height-based error correction equation to obtain accurate readings. I decided to fabricate the Coolar with a mix of PLA plastic for internals and forged carbon fiber for the exterior. To use carbon tow without a heating oven, I used a room temperature forging method, mixing resin and epoxy and using 3D printed compression molds to create the carbon fiber part. In the future, I plan to use a PCB to decrease manufacturing time and increase the accessibility of the Coolar for consumers and businesses.