Miniature Underwater Robotic Fish for Animal-Robot Interactions

Research in animal behavior has benefited from the availability of robots able to elicit controllable, customizable, and versatile stimuli in behavioral studies. For example, biologically-inspired robotic fish can be designed to mimic the morphophysiology of predators and conspecifics to study fear response and sociality. However, size is a critical limitation of the existing arrays of robotic fish. Here, we present the design of a miniature robotic fish for future animal-robot interaction studies featuring a novel application of multi-material three-dimensional (3D) printing and utilizing a solenoid for actuation. The use of multi-material printing enables a skeletal design of only two parts, while retaining the complete functionality of larger prototypes enclosing requisite electronics and incorporating an active joint for propulsion. Parametric tests are conducted to test the swimming speed of the robotic fish and a compact dynamic model with two degrees of freedom to elucidate swimming of the robotic fish is presented.