David L. Hu


On his book How to Walk on Water and Climb up Walls: Animal Movement and the Robots of the Future

Cover Interview of March 27, 2019

The wide angle

Understanding animal motion requires application of physics, material science, and robotics.

Take an insect walking on water called the water strider. Its legs are covered in the hairiest surface in the animal kingdom. The 10,000 hairs per square millimeter help trap air bubbles and prevent the legs from getting wet with each stroke. We apply fluid mechanics to understand how the legs can support the strider’s weight and propel it forward. Robotic design is used to build lightweight robots that can walk on water by taking advantage of the size and forces applied by the legs. These robots are given solar panels or other lightweight energy storage devices that enable them to be mass produced and used as cheap ways to monitor the world’s oceans.

When I was a kid I loved going to the zoo and watching animals. When I was admitted to MIT, I learned that the tools of engineering could be useful to understand the amazing things that animals do. I combined this with a PhD in mathematics, and now I run my own laboratory as a professor in both mechanical engineering and biology at Georgia Tech. Our lab studies the design of animals and builds devices based on the things we learn.