A robotic hand can be designed in different ways. The most important is that there is a wrist, fingers, and a way to move an object. The wrist will give the twisting motion. The fingers will be able to grab an object. Some people use grippers. The grippers work like sicorrs. There are also devices that act like sensory nerves. These devices are either light sensitive or switch activated. That way a robot would be able to tell where a light source is coming from or when it was running into a wall. The hardest part about making a robotic hand do something is to make the open and closing motion with the fingers. Humans have nerves and muscels that alow them to retract and contract their fingers. With a robot cables, motors, or pneumatic hydralics can be used. Strong cables can be used to give easy and quiet movements. Motors used with different gear ratios can make the fingers stronger when gripping or faster. By determining how much work would have to be done on the gear to make it spin would make the gear lift an object with force. There are factors such as the torque, angular velocity and friction of the gears or cable that would have to be taken into consideration.
Here are some formulas that would need to be used to find out the Force and Torque.
T=r*(F sin0) T=I(angular acceleration) (Number of teeth on the intial gear)/Force applied = (Number of teeth on the final gear)/Force final
(change in Kinetic Energy) = [(1/2)Iw^2f - (1/2)Iw^2i] = Work