Hi Andy,

First, I don't really have any experience with this technology, except as follows.

Back in the early 1980's I worked at an alarm company. We used a module to protect safes called a "proximity detector," (a suggested search term, in an alarm/security context). The distinction between a touch sensor and a proximity sensor is that you don't need to physically touch a proximity detector. You just need to get close to whatever metal it is in contact with (in our case, a safe). That would address any problem with people wearing gloves.

As I said, I've never fooled with any of this from the electronics aspect. However, I suspect it's just a Wein bridge. A body getting close enough would alter the capacitance, and a level detector would adjust the "sensitivity." I would suggest you do more searching with these terms and see what you can find.

Good luck.

Joe