Giving Snakes Their Mobility Back with a Set of Artificial Legs

A brief biology lesson

Snakes have been around since at least the Jurassic period, or about 150 million years ago. They are believed to have evolved from either burrowing or aquatic lizards, which ditched their legs for a smooth, scale-covered body that can slither on the ground. This fact spurred prolific maker and YouTuber Allen Pan to do something out of pity, as he felt sad these animals have been unable to find their legs since.

Building the initial prototype

Inspired by some of the prosthetic legs built for our mammalian companions, Pan began with an off-the-shelf solution that incorporated a pair of robot hexapods into a mobile platform. Each robot operates similar to a crab and provides plenty of stability, while the blood pressure cuffs on top hold the snake in place. However, the lack of a supporting structure in the middle could lead to injuring the scaly reptile, meaning a revision was needed.

Creating a better set of legs

In order to remedy these problems, Pan designed a set of four legs in Tinkercad that each consisted of two segments. Both the front and rear pairs of legs were joined by a simple, flat connector that contained a servo motor on each side for side-to-side movement, along with a cutout in the middle for attaching the transparent snake containment tube. The legs are able to raise via another pivot point and servo motor.

The gait

All eight servo motors are powered by a single LiPo battery pack that provides sufficient current when loaded down with a snake's weight. They are also connected to a dedicated servo controller board that can not only be loaded with external programs via a host PC, but also controlled wirelessly. Because snakes are descended from lizards, Pan took a trip to a pet store and carefully observed how the lizards there moved their legs in an alternating pattern. After translating these motions into a series of servo instructions, it was finally time to test this device.

Testing with a real snake

Pan began his experiment by first loading a snake into the central chamber while taking care to prevent potential injuries to either himself or the snake. Due to the intrinsic servo shakiness, he was forced to disable the servos when loading the scaly reptile because of their sensitivity to vibrations. But after a little bit of wrangling and waiting, he was able to drive his prosthetic leg system forward, and thus, return the snake to how it was meant to be (in his opinion). To see more about the journey of how this project was created, you can watch Pan's video here on YouTube.