Ingo Cyliax wrote:
> As capacitor, any large metallic surface will work. It helps to
> have a large ground counterpoise. Your idea of using foam/foil
> should work well. Capacitive sensor will sense many materials,
> the measure the e-field and thus how materials change this from
> air, but water or humans work best.
I'm not sure I've explained correctly. Basically, I'd like to use
capacitive elements as force sensors by capacitively sensing the
proximity of the foil. The actual capacitor/sensor-pad would be a
separate metallic sheet or interdigitated pattern on the opposite side
of the foam, which could have it's own grounding plane to prevent the EM
field from extending backwards. I'm simply trying to get around the
"water or humans work best" limitation. Also, when used as a skin, the
upper layer of foam/foil would have the benefit of being easily
repairable, while maintaining full sensitivity of the sensor.
Is this approach practical? It seems simple enough that if it were,
someone else would already be using it in a robotic application.
And please, respond to the group for everyone's benefit.