Meniscope: A Low-Cost Fluid Interface Visualizer

In this work, we describe the development and application of a low-cost fluid interface visualizer referred to as the "Meniscope." The device works using a color-based surface gradient detector method that maps the gradient of an air-water interface to a specific color on a target pattern below using a converging lens. Sample experiments are outlined that showcase the working principle and functional versatility of the device, with direct connections made to related biological phenomena. The device and assembly instructions were piloted in a hands-on workshop, with pertinent feedback reviewed herein. The Meniscope is a low-cost device that is capable of producing striking visualizations of static and dynamic free-surface deformations while introducing users to free-surface measurement techniques in an accessible and hands-on manner.