Saline oscillator as a teaching experiment

Abstract

The saline oscillator consists of two aligned containers that are filled in by a pair of different solutions, exhibiting electrical potential oscillations when released. These oscillations occur due to a difference of mass density presented by the fluids and they cause varying ions flow, leading to electrical potential variations between both reservoirs. Many biological systems can be understood by this model. In this work, the saline oscillator was investigated using copper sulfate, CuSO4, and sodium chloride, NaCl, solutions, changing parameters as the diameter and length of the capillary, diameter of the internal compartment and amount of unwanted ions in the main reservoir (distillated and deionized water). The system is shown to be very useful in undergraduate teaching classes.