​When I started with this project, I had an old phone. It would lose its battery within a few hours, even with battery saver on. I wanted to use my frustration with this piece of junk phone to create a seamless way to charge your phone throughout the day. Through a little bit of research, I realized we are still very rudimentary with our charging methods. I think its fair to say that everyone's most common way to charge is via a wall outlet. I wanted to explore other ways using renewable energy.

 

My goal with this project was to create a sweatshirt that harnesses excess body heat to produce enough electricity to charge a phone. I attempted this by using thermoelectric generators (TEGs), that produce electricity based on a temperature difference. Now these sounded

perfect for what I wanted to do. Just strap a few of these to the

warmest parts of the body (anywhere around the heart, really), steady

the voltage at 5 Volts to charge a phone, and that'll be that. It was not

that simple.

 

After a short amount of testing and some disappointing

research, I found out these thermoelectric generators were about 10%

efficient. Body heat could create around 0.08V for about a minute before the body heat dissipated to both sides of the TEG, producing no electricity. So, I sent an email to a company making more efficient, flexible TEGs called Tegway. Unfortunately, I still haven't received a response.

 

So I went back to what I had. Maybe I just wasn't holding it tight enough to the body. Maybe if I strapped more of them to the body with elastic I could produce more electricity. Now came the challenge of trying to strap                                                                             these TEGs to the skin without covering up the side exposed to the air.                                                                       So I taught myself how to 3D print, and began trying to make frames                                                                           for the TEGs with little slits on the sides for elastic to wrap around. This                                                                       took a few attempts to get right, as I adjusted for millimeters of space                                                                         to fit the TEG snuggly.

 

                                                                     Once I got a design I was happy with, I was able to mass produce the    frames, learn how to sew to connect the frames, and solder the TEGs in  a series circuit. I added another row of TEGs, like the one below for a total of 10 TEGs to be strapped to the body.