contact force sensing

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It seems that there is a bump/force sensor that works for contact on a link. However, does this scale or is there another implemented sensor that would allow me to get contact forces all over a robot arm? Essentially, I'd like to simulate tactile sensing. I have implemented and used something similar in ODE directly, but wondered if the contact joint API was exposed in Gazebo. Or if it would be possible to write a plugin to do get the forces. Any help would be much appreciated as I'd really rather use Gazebo.

thanks.