3-D Printing and Arduino in the Chemical Engineering Classroom: Protein Structures, Heat Exchangers, and Flow Cells

Unlike other engineering disciplines, chemical engineering (ChE) students rarely get the opportunity to design and build models, devices, and prototypes in the classroom. ChE students are also less likely to obtain valuable skills like computer-aided drafting (e.g., AutoCAD or SolidWorks), programming (e.g., Arduino), and circuitry. These are undeniably useful skills, but it is often challenging to find practical ways to incorporate them into ChE courses that are already dense with material. This paper describes 3 different modules that simultaneously teach core ChE & BioChE concepts while also introducing the concepts of 3D printing, drafting, and programing/circuitry with Arduino. The overall goal is to use these interdisciplinary techniques to enhance the students’ understanding of ChE concepts. Module 1: 3D-Printed Amino Acid Building Blocks to Teach Protein Structure This first module uses 3D-printed alpha carbon atoms (C) and peptide bond groups (CONH) to show students how amino acids assemble into peptides and form complex structures simply by rotating the bonds around the alpha carbons. Students can use the models to prepare their own Ramachandran plots or build secondary structures (e.g., alpha helices and beta sheets). No drafting or coding experience is required for this module, but a 3D printer is needed to print the parts. Module 2: 3D-Printed Plate & Frame Heat Exchangers This module allows students to design, build, and test their own plate & frame heat exchanger. The plates for the heat exchanger can be easily drafted in SolidWorks and modified to include corrugation or other geometries that increase turbulence and heat transfer. The 3D printed plates can then be assembled and used for heat transfer experiments in which the students estimate heat transfer coefficients. Coding can also be included by using an Arduino to monitor inlet & outlet temperatures with thermocouples. Module 3: An Arduino-Controlled 3D-Printed Flow Cell to Measure Enzyme Kinetics In this module, students design and build their own rudimentary spectrophotometer, which consists of an LED light source, photoresistor, cuvette, and an Arduino. The Arduino powers the LED and uses the photoresistor to measure how much light passes through the sample in the flow cell. This flow cell can be used to monitor chromogenic chemical reactions, including the reaction of beta galactosidase with ONPG, which produces a yellow product that absorbs light. Varying the concentration of ONPG allows students to collect data for Michaelis-Menten plots. Note: Materials for each module are available from the primary author upon request.