Brain scanning (EEG) and stimulating (TDCS) devices, which were initially used for clinical research, are now being used for a host of commercial and military applications. However, all of these applications can be DIY’d using commercially available parts. This demo will focus on how you can implement two of the most cutting edge brain-related applications. The first is Brain Based Authentication, which is a way to use brain signals as a unique personal identifier. The second is TDCS, which is a way to modify brain function using electricity. Throughout the session we will discuss the neuroscience underlying these techniques, as well as their reliability and ethical ramifications.