Summer can be a magical time, one of of hot days, late nights, and lifetime memories. Those unforgettable moments that we carry with us long after the season itself ends.
At least that is what I have heard from the Gossip Girl novels and Tumblr. In my actual personal experience, I (and my unfortunately lackluster ability to regulate my body heat) tend to spend most of the summer months either holed up in my nicely air-conditioned workplace or laying on my floor at home whilst sweating and complaining.
I have long dreamed of a way to shed this suffocating heat, and while many find refuge in nearby lakes or pools, all I have access to here in Pullman Washington is a questionable stream downtown and a small fountain by the library that is apparently “not for that use”. Well, Thomas Edison once said that genius is 99 percent perspiration and 1 percent inspiration and by god I already had the sweating part down, so all that I needed now was the idea.
So, after some pondering I came to the conclusion that the answer was going to involve building myself some sort of AC system. Unfortunately I figured that I possessed neither the technical skills nor the money to build a D.I.Y swamp cooler, so after some careful consideration and the abandonment of any moral obligation toward anyone but myself, I decided to focus on how to build a personal AC system.
You see, I figured it would be easier and take less power to just alleviate one person of the heat instead of a whole room/house… plus my last pack of Oscar Meyer hot dogs had recently undergone a mysterious disappearance, so I decided to remove my housemates from the consideration pool.
Alas, the Personal Cooling System was born.
The design involves running ice-cooled water through tubes that are held again heat-sensitive parts of the skin. The current setup includes a “Cooling Pack” that is kept pressed against the back of the wearer’s neck, which is automated to be sent fresh, cool water when a button mounted on the shoulder is pressed. The intent is to allow for an efficient, portable, reusable cooling system.
I used a chipKIT uC32 as the brains of the project, which is able to control two servos which are attached to the syringes. The code runs off the push of a button and each time cycles ice-water from the CamelBak to the Cooling Pack.
This project is currently a bit of a work in progress, however it does function as intended even if it is not the most…attractive looking aesthetic. My next steps include hiding the mechanics within the backpack so I can carry it outside without attracting judgmental looks from strangers and law enforcement, as well as adding a sweat sensor for autonomous cooling (without having to press the button each time).
I am planning on using the concept of galvanized skin response to create the sensor, then setting a threshold in the code for at what point the wearer is “too sweaty” and needs cooling.
An awesome example of a project that uses similar design comes from a 2016 finalist team in the Digilent Design Contest Europe.This team created a Wearable Wellness system using the Zybo ARM/Zynq FPGA development board, PmodOLED, PmodRF2and PmodIA that can measure changes in skin impedance.
While their team focused on the stress aspect of wellness, it could also be applied as a sweat sensor so your Cooling System would be completely autonomous.
Feel free to check out the full instructions on how to make the Personal Cooling System for your own usage with my Instructable, and let us know how you intend to beat the heat this summer!