$1 Liquid Cooler

After reading some papers on cooling the human body through pulse points I decided to build this prototype.

The human body has several pulse points, one of the major ones is in the wrist where blood flows very close to the skin. When these areas are cooled the entire body is effectively cooled as the cooled blood is pumped around bringing down your body temperature.

If this ends up working I wanted to make a portable rig to wear while riding my motorcycle in 100F+ weather.

This uses a United states $1 coin and it fits quite snugly with a small bead of hot glue to seal it. My print actually leaked through a few of the layers very slowly, a drop every 30 seconds or so, but that's only because I had recently changed filaments and the new filament needs to be printed at a higher temperature, that is fixed now.

It needs more work, the hose barbs should be made glue in instead of one piece so they can print vertical so they stay round.

As far as testing I pumped tap water, around 75F through it with a small pump at a quite slow rate, the output tube was barely a stream, and I applied a 40W soldering iron to the coin for several minutes and you could put your finger on the coin right next to the soldering iron and it stayed cool to the touch.

EDIT
Added a spiral based cooler in an attempt to increase flow. It has been printed and printed perfectly, but has not been tested yet.