Edible robots could be incredibly useful for delivering medicine, but there’s one small problem. Batteries and actuators, the things necessary to power robots, are very inedible. But a team of researchers from Dario Floreano’s Laboratory of Intelligent Systems at EPFL in Switzerland has found a way to make a moving robot that you really can eat, battery and all.
The battery is made from liquid citric acid and baking soda stored in two chambers separated by a membrane layer. When pressure is applied to the chamber with the citric acid, the membrane is punctured and the citric acid slowly drips onto the baking soda. This generates CO2 gas and sodium citrate (which is safe to consume). The CO2 then travels through a gelatin tubing into the actuator, putting it under pressure that makes it bend. The robot is capable of about four bending cycles per minute and can run for a couple minutes.
And it isn’t useful just because it’s edible — this little bot is also very environmentally friendly. “A potential use case for our system is to provide nutrition or medication for elusive animals, such as wild boars,” said lead author Bokeon Kwak. “Wild boars are attracted to live moving prey, and in our case, it’s the edible actuator that mimics it.”
