I have been handed a challenge that is beyond my reach. I need a way to detect the change in skin conductance, or some other electrical signal on the surface of your hand when you lightly touch your forefinger and thumb together. In this configuration, the skin sensors have to be located on the wrist, I don't have access to the fingers directly. I can't use tendon or muscle movement as my signal, it has to be light touching of the skin. I just need a yes/no indication, touching or not touching. Detecting a passive signal would be best, since it needs to be low power. I know the human body acts as an antennae picking up 50-60mhz a/c perhaps there is a way to play off of that phenomenon, and measure some change in the antennae configuration when the thumb and finger complete the loop? Could that work? Any other ideas?