This just came in as a comment, I’m reposting as a post. I don’t know the author and have not corresponded with them as of yet. I can confirm that the originating email address has a upen.edu footprint.

Hi,

You are being invited to participate in a research study conducted by
the University of Pennsylvania. Your participation is voluntary which
means you can choose whether or not you want to participate. 

The Laboratory of Cognition and Neural Stimulation at the University of
Pennsylvania is involved in research using transcranial direct current
stimulation (tDCS). In recent years this technology has increased in
popularity, and evidence suggests that some individuals may be
constructing their own stimulators for personal use. We are interested
in examining the reasons behind this. Please answer the questions below,
and email them to braintdcs@gmail.com to give us insight into why people
make their own tDCS machines.

Questions

1.	Where did you first learn about tDCS?
2.	Have you built your own tDCS machine?
3.	Where did you get the information to build the machine?
4.	Why did you want to try brain stimulation?
5.	How long have you been using tDCS?
6.	What were your experiences with this technology?
7.	Did you ever experience any side-effects?

The research team may use information about you collected from your
responses. By completing the questionnaire, you are giving your consent
to participate in this study. Once you email us, your responses are not
considered confidential since emails do not protect confidentiality.  

Thanks,

Research Specialist
Laboratory of Cognition and Neural Stimulation
University of Pennsylvania