The below MPSA13 transistors are very sensitive (MPSA14 even more so). I used one to make a coffee can ion chamber to detect Thorium in lantern mantles. You might also look into capacitive touch sensors for a touch switch.
The below MPSA13 transistors are very sensitive (MPSA14 even more so). I used one to make a coffee can ion chamber to detect Thorium in lantern mantles. You might also look into capacitive touch sensors for a touch switch.