Direct Current (DC) Electric Field-Enabled Beating Heart of Ga-Based Liquid Metal

Mercury beating heart (MBH) is a well-known demonstration of redox processes. However, the development and application of the MBH system are significantly restricted due to its safety issues. Here, a direct current electric field-enabled gallium-based liquid metal heartbeat in a salt solution or alkaline solution is introduced as a demonstration appropriate for undergraduate general chemistry. The former oscillation occurs on the cathode, the latter on the anode. The objective is to achieve a visually appealing effect in the classroom and motivate students to understand the underlying concepts. Students are encouraged to assemble the instrument and perform the demonstration under supervision. Apart from the gallium-based liquid metal and a helping-hand stand, the demonstration utilizes common laboratory apparatus, and the materials for the solutions can be obtained in an undergraduate general chemistry laboratory.