Analog robot
An analog robot is a type of robot which uses analog circuitry to go toward a simple goal such as finding more light or responding to sound. The first real analog robot was invented in the 1940s by William Grey Walter. The name of these robots were ELSIE and ELMER (Electro Mechanical Robot). The original circuitry was developed using two vacuum tubes and a photocell to search and follow a light. Recently a kind of analog robots was developed by Mark Tilden.
Animatronics
In 1515, Leonardo da Vinci designed and built the Automata Lion, one of the earliest described animatrons. The mechanical lion was presented by Giuliano de’ Medici of Florence to Francois I, King of France as a symbol of an alliance between France and Florence. The Automata Lion was rebuilt in 2009 according to contemporary descriptions and da Vinci's own drawings of the mechanism. Prior to this, da Vinci had designed and exhibited a mechanical knight at a celebration hosted by Ludovico Sforza at the court of Milan in 1495. The 'robot' was capable of standing, sitting, opening its visor and moving its arms. The drawings were rediscovered in the 1950s and a functional replica was later built.