My DS4 is also similar - born scientist/engineer.

While I have not tried the tinkering sites/activities listed below yet, the sites might provide ideas or materials for your DS. One is relatively nearby in Tacoma.

http://www.ted.com/talks/gever_tulley_s_tinkering_school_in_action
http://www.tinkeringschool.com/what-is-tinkering-school/
http://tinkering.exploratorium.edu/about
http://tinkertopia.com/