Application of Ambient Pressure-Driven Pumping Technology for Underwater pH Measurement

In this study, the power-free pumping technology utilizing ambient hydrostatic pressure in the underwater environment was applied to realize a $\mathbf{p H}$ measurement system with an in situ calibration capability. A glass microfluidic pressure reducer was connected to a 3D-printed fluidic platform containing a pH sensor device for the evaluation of the flow-switching performance to supply $\mathbf{p H}$ standards and a seawater sample. As a result, the microfluidic pressure reducer and fluidic platform worked properly with unfiltered natural seawater sample.