Multiple servo motors to control joints like the "waist," "shoulder," and "gripper".
A skateboard-like base, often 3D-printed or laser-cut.
Some advanced scripts allow users to "record" a sequence of moves and replay them.
An Arduino Uno or Mega serves as the "brain," processing code and sending PWM signals to motors.
Robotic Arm with Arduino - Save/Play/Export/Import Positions.