Daniel C. Harris
Mechanical Engineering and Applied Mechanics and Robotics
FRIO​​
A Personal Cooling Device
FRIO is a lightweight and unobtrusive personal cooling device designed to be worn on the wrist. It uses evaporative cooling technology whereby a fan blows room temperature air onto TENCEL fabric, which saturates itself with water from a 60 mL reservoir. A thin copper sheet is positioned directly underneath the fabric. By doing so, the forced evaporation of water within the fabric effectively drops the temperature of the copper sheet to as low as 50 degrees Fahrenheit with no thermal load - this is however highly dependent on the temperature of the surrounding air. This copper sheet is then used to conduct heat from your skin while exhaust air is redirected both up and down the user's arm for additional convective cooling. Over a transient time of ~8 minutes, the user experiences a full body cooling effect.
A 3.7 V 250 mAh lithium polymer battery is used as the power source for the fan. To optimize for space and cost, a custom printed circuit board (PCB) was incorporated into the design. This PCB both boosts the nominal voltage to 5.0 V as well as includes a charging circuit that notifies the user once charging is complete. A provisional patent for this technology was filed and approved in February 2018.
