The invention relates to a mechanical finger comprising, a knuckle, a proximal element, a rod, a motor, a motor driven screw and a distal element. The knuckle has a first and second pivot. The proximal element knuckle end is coupled to the first pivot. The proximal element also has a third pivot at a variable longitudinal distance from the first pivot. The rod has a near end pivotally coupled to the second pivot and a far end pivotally coupled to the third pivot. A motor is coupled to and referenced to the proximal element. A screw is driven to change the distance between the third pivot and the first pivot in response to a command from a controller to the motor. A distal element is pivotally coupled to the proximal element. The distal element rotates with respect to the proximal element in response to a change in the variable distance between the third pivot and the first pivot.