Towards a biologically inspired small-scale water jumping robot

This paper describes the locomotion of a water jumping robot which emulates the ability of the water strider and the fishing spider to jump on the water surface. While previous studies of the robots mimicking aquatic arthropods were focused on recreating their horizontal skating motions, here we aim to achieve a vertical jumping motion. The robot jumps by pushing the water surface with rapidly released legs which were initially bent. The motion is triggered with a latch driven by the shape memory alloy actuator. The robot is capable of jumping to the maximum height of 26 mm. Jumping efficiency, defined as the ratio of the maximum jumping height on water to that on rigid ground, of a currently developed model is 0.26. This work represents a first step toward robots that can locomote on water with superior versatility including skating and jumping.