After using this equation I've come to a few questions and concerns about the physics of it. The only article I could find over the amount of force necessary for a robot hand to hold an object in the air produced the following equation: where is the force required, is the coeffecient of friction, is the number of fingers on the gripper and is the weight of the object held. It seems counter-intuitive to me. If you increase the amount of grippers, more force needs to be applied? The higher the coefficient the more force needs to be applied? What... Using this formula I came to the conclusion that with a of 0.8 between a human hand and a metal object of 43 kg, with 5 fingers, it would take 1,687N to hold it in midair. I need to know if I'm doing it right or if these numbers are totally out of the ballpark.