Claw construction

I want a claw that doesn’t apply torsion to the book. This means we can’t have angular motion, at least not without a lot of tomfoolery. My initial(ious) thought is a servo driven grabber. Add some feedback and we can make sure we always have the right amount of pressure (one I get that calibrated, and probably add a mass value per title). Or, maybe I should do a load cell. Huh.That might be a good idea…