Providing students opportunities to appreciate interdisciplinary systems remains a challenge for educators at all levels. Sensing and data-logging in the environment and in engineered systems offer a unique opportunity for students to explore the connections between engineering processes, analog signals, and digital outputs. Here, we present the design of a device that uses an infrared sensor and microcontroller to measure and record low liquid flow rates. We designed this device using the open-source Arduino T microcontroller platform, which can stand alone or interface with a PC to display data in real time. In order to demonstrate the usefulness of this device in the undergraduate learning laboratory, we have incorporated it into a membrane distillation system. Building and experimenting with such devices helps students practice and learn creativity, troubleshooting, and programming fundamentals, allowing them to understand the importance of electrical engineering and computer programming in the context of chemical and environmental engineering.