Low-Cost 3D-Printed Contact Angle Goniometer for Materials Science and Chemistry Education and Research

We present the design and validation of a low-cost, 3D-printed contact angle goniometer aimed at supporting education in materials science and surface chemistry. The device, with a total cost below €100, has been designed following different strategies to optimize usability and ensure intuitive handling by undergraduate students. With minimal training, users can independently visualize wetting phenomena and quantify surface properties using open-source tools. The setup includes a digital microscope that connects directly to any computer, enabling image acquisition as a standard video feed. Image analysis is performed easily with the freeware ImageJ using an open-access plugin. Comparative measurements demonstrate that the data obtained with this low-cost system are consistent with those produced by commercial instruments, making it suitable for use in materials science or physical chemistry laboratory courses, as well as in undergraduate and master’s research projects.