<p>When Yoichi Masuda set out to design a new legged robot, he found inspiration in the Martian <a href="https://en.wikipedia.org/wiki/Fighting_machine_%28The_War_of_the_Worlds%29">Tripods</a> from the classic sci-fi novel “<a href="https://en.wikipedia.org/wiki/The_War_of_the_Worlds">The War of the Worlds</a>” by H.G. Wells. A three-legged configuration seems to offer some advantages when it comes to walking and balancing, and Masuda became curious about the absence of three-legged animals in nature. Are there evolutionary factors that explain why we haven’t seen any? And if three-legged creatures existed, could there be a universal principle of walking locomotion, common for bipeds, tripeds, and quadrupeds? To explore those questions, Masuda and his colleagues at Osaka University built a three-legged robot named Martian.</p>
<p><img src="http://spectrum.ieee.org/image/MjkzNjg2NA.jpeg" width="200" height="150" /></p>