(253c) Safe Take-Home Experiments for Chemical Engineering Education

In this talk, we will present a recent pilot case study we led in the Singapore Institute of Technology. The study aimed to deploy experiential learning in a Year-1 Python Programming course with a class size of 114 students. Approximately, 40 low-cost, lunch box-sized devices were assembled for students to appreciate the concept of automation. Each device was a plastic box, containing a micro-controller, a CO₂ sensor, a fan, and a bowl (cost of each device: ~40 USD). In a group project (size of most groups: 3), students took the device home and turned them into CO₂ incubators. They were instructed to prepare a solution containing yeast and sugar in the bowl to produce CO₂. The micro-controller has been programmed for them, so that students could send simple commands from their laptop to the micro-controller via Serial communication for requesting CO₂ data and controlling the ventilation fan. Most groups have met the technical specifications (maintaining CO₂ in the range of 4,000 ± 200 ppm for at least one hour). In the project, students practiced the basic programming techniques they learnt in the theory part of the course, especially recursion, conditional statement, various variable types, data management using DataFrame, and data visualization. They also experienced how a closed-loop control system works and found the “tricks” needed to manage the deviation from the setpoint. Many of them have used proportional control after they realized that the On-Off control could not meet the objective. They have also witnessed a steady-state error and could not address it without manually offsetting the setpoint. This experience should help them understand and appreciate the PID control theory in their Year 3 course. The project also had an open-ended component where they were tasked to design interesting experiments using the device. The official student feedback report is not available when this Abstract was submitted, but some students actively approached the lecturer to express their positive feedback on the project.

We will also briefly discuss how the modular device can be expanded to conduct more experiments outside standard labs for Chemical Engineering education. It will rely on biocatalysis to carry out experiments under mild conditions and utilize low-cost sensors (e.g., light, temperature, weight, pH, camera) and actuators (e.g., LEDs, peristatic pump, heating element, agitator). Such activities could complement the existing standard lab sessions and allow students to have more hands-on activities with less time and resources constraints.