Step 1: Overview
In this instructable, I will show you how to make and use a "brain cap" a tDCS device that can be worn while it is being used. tDCS stands for transcranial direct current stimulation, a form of brain stimulation involving direct current (aka a battery) that can be used to treat depression, chronic pain, and other illnesses as well as reduce time needed to learn certain tasks. It does so by passing a small electrical current through the skull, which stimulates a certain patch of neurons. Don't worry, tDCS is completely safe; it only produces 2mA of current. To learn more, I would suggest searching "tDCS" in your browser since there are a lot of good articles on it online.
Step 2: Safety
-Never use a power source that isn't a 9 volt battery. You run the risk of exposure to a high current, which can be life-threatening.
-A 5mA fuse is part of the list of materials. Though it is not required for the circuit to work, it is HIGHLY RECOMMENDED! Currents over 5mA can be harmful if not deadly.
-Do NOT use tDCS for more than 30 minutes at a time. Doing so isn't necessarily hazardous, but you may get a headache.
Step 3: Materials
For the Circuit:
-LM334Z Voltage Regulator $4.25
-33 Ohm Resistor $1.50
-9 Volt Battery $18.00
-5 milliAmp Fuse $27.00
-Toggle Switch $4.00
-Battery Clip $3.00
-2 Amrex sponges $10
For the Hat
-Baseball Cap $15.00
-A small platform to mount the circuit (optional, so no price or seller listed)
For Construction and Operation
-Soldering Iron $10.00 http://www.amazon.com/gp/aw/d/B0006NGZK0?pc_redir=1399143411&robot_redir=1
For Each Use
-Water (from the tap)
-Salt (regular table salt)
Some of these materials you may already have; that should cut the cost of this project. Also note that I did not use some of the products that I linked to to make my device.