Miniature joysticks are small electromechanical devices, finger operated, which convert the input force of the operator into an analog output voltage, proportional to the applied force and supply voltage (isometric control).
The conversion applied force - output voltage in accomplished through a beam, acting as a cantilever, on which strain gages are bonded and to which is applied by means of a knob.
Dual Axis joysticks, converting force components along two orthogonal axis into two distinct ouput voltages, are the standard.