Best (lest invasive) way to sense contact between thumb and index ?

Hello,

I want to use the contact between my thumb's end and my index's side without having to put a sensor on the thumb's end.

First I was thinking about a pressure sensor put on the index's side but now I am wondering if there's a better solution (maybe even a way to sense a capacitive change without any sensor ?)

Any idea ?

Thank you in advance.

you can also use a flex sensors .

Problem is that you never are sure that the index and thumb touched, it can allways be pressed /flexed for some other reason

or use two thimbles (dutch vingerhoedje) which can make contact.

Timbles would be more appropriated for finger's tips, wouldn't they ?

what do you want to accomplish? with the touch should something gets started or …

I have built a 3D tracking system based on the hand's position and I need an additional switch to start/stop the tracking. Also I don't want to hold anything because when the tracking system is not used the hand should be free for other tasks (move the computer's mouse or the sliders on a MIDI controller, etc).

sounds like you need a dataglove?? - http://vimeo.com/channels/60193/page:2 - ??

No, what I have built yet is working fine so I just want to add one switch.