If you were stranded on a desert island, what is one item that you would bring with you? A cherished book? A roll of duct tape? A roll of toilet paper? If I were stranded, I would want a robot that could write "help" in large, legible letters in the sand. Luckily for me, this survival must-have has already been designed and created by Ivan Miranda. His unique sand-drawing robot can print any text using nothing but sand.
According to David Grossman for Popular Mechanics: "The text looks a lot like a dot matrix format from the 60s and 70s, and that's for a good reason. Miranda is using a large linear actuator on large wheels, slowly moving one column at a time. It writes vertically, making indentations in the sand with a marker that drops up and picks up to fit each letter. The skinny columns give each letter maximum visibility.
The trade off is speed. Much of the video is spent on fast forward, speeding up what appears to be a time consuming process. That could present some trouble on a beach, where wind (or other beachgoers) might erase a message before its written."
If you are more interested in images than text, check out this Disney sand-drawing robot.