From Spark to Fire─Preparation of Molecular-Based Piezoelectric Material, Fabrication of Devices, and Demonstration of Piezoelectric Effect: An Innovative Experiment for First-Year Undergraduates

For the first-year undergraduates, electronegativity, molecular polarity, dipole moment, etc. are all relatively abstract concepts and have been covered in inorganic chemistry or general chemistry courses. In fact, the piezoelectric effect is the macroscopic expression of electric dipole moments and molecular polarity in solids, which is the ability to convert mechanical stress into electricity or vice versa. Based on recent research findings in molecular-based piezoelectric materials, we designed a laboratory experiment including the synthesis of molecular-based piezoelectric material N(CH3)4GaCl4, the fabrication of piezoelectric devices, and the demonstration of piezoelectric effects by illuminating LEDs in order to help the first-year undergraduates to understand these concepts. This experiment enhances students' comprehension of relatively abstract concepts such as molecular polarity, dipole moment, and the piezoelectric effect. And this experiment not only bridges the gap between cutting-edge research and basic chemistry laboratory teaching but also effectively integrates fundamental principles, methods, and experimental skills related to the inorganic compound preparation and separation, piezoelectric effect generation, and piezoelectric device fabrication. It is a multidisciplinary experiment that covers chemistry, materials science, physics, and energy-related themes, fosters students' interest in hands-on experimentation, and cultivates their ability to apply theoretical knowledge in practical circumstances. The experiment was carried out successfully in 1 round by 350 first-year undergraduates majoring in chemistry, chemical engineering, and materials science and engineering at Xiamen University and was well received by students and teachers.