Does anyone have experience picking sheet metal from a stack using vacuum.  In this case there are separator sheets, but the problem is that the pieces like to stick together because all of the air in between has been pressed out.  We have tried several different techniques of lifting off, but every time one or more pieces in the stack are moved out of position.

Any advice would be appreciated.

Thanks for the info Matt, we were trying to accomplish this with just the robot's movement.  The other trick is that we probably don't have the best style vacuum end effector for the parts (we're doing a quick proof of concept in house).

The only motion we ever got was to peal the sheet back and twist at the same time but even that wasn't reliable so we went with separation magnets and voilá, issue resolved