Abstract: Flapping flight is ubiquitous among agile natural flyers. Taking inspiration from biological flappers, we develop a robot capable of insect-like flight, and then go beyond biological capabilities by demonstrating multi-phase locomotion and impulsive water-air transition. In this talk, I will present our recent research on developing a hybrid aerial-aquatic microrobot and discuss the underlying physics. I will start by describing experimental and computational studies of flapping wing aerodynamics that aim to quantify fluid-wing interactions and ultimately distill scaling rules for robotic design. Comparative studies of fluid-wing interactions in air and water show remarkable similarities, which lead to the development of the first hybrid aerial-aquatic flapping wing robot. In addition to discussing the flapping frequency scaling rule and robot underwater stability, I will describe the challenges and benefits imposed by water surface tension. By developing an impulsive mechanism that utilizes electrochemical reaction, we further demonstrate robot water-air transition. I will conclude by outlining the challenges and opportunities in our current microrobotic research.