Off-the-shelf pickup sticks only work if the person has the grip strength needed. Also, the gripper only works when closing around the outside of an object, and can't adapt to variations in shape. My project is a single-servo, planetary gear actuated, three-jawed alternative that has variable speed, and force limits.
The fingers are special triangular, pivoting shapes that adjust to a wide variety of objects, and can even pickup objects by opening from the inside.
The planet carriers and the ring gear have auxilliary jaws which provide the ability to grip even very small objects, while the three-jawed mechanism handles the larger objects, including door-knobs.
Designed in FreeCAD; Printed on an UP!Mini 3D printer in ABS; Dynamixel AX-12A servo driven; Arduino controlled