DraBot is an electronics-free bot that moves in reaction to environmental conditions such as acidity, temperature, or the presence of oil. Here’s more from SlashGear:
When the water is acidic, one front wing fuses with the back wing causing the robot to spin in a circle rather than travel in a straight line. When the pH returns to normal, the fused wings separate, and the bot is responsive to commands. The researchers also placed sponges on the robot that will soak up oil and change color, indicating its presence. DraBot’s wings also change from red to yellow color if the water is too warm.
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