Ivan Miranda has come up with a novel method for drawing messages in the sand, using a tread assembly that prints as it travels along the beach.
The robot uses a length of square tubing to connect a pair of half tanks, with 50 SG90 micro servos spaced out on the bottom. As it pulls itself, the motors are controlled with a total of three Arduino Mega boards, intermittently extending into the sand. This creates lines that combine to form individual letters.
An interesting link found among my daily reading