A study on the repeatability of electroformed electrochemical gas driven micro-pump, using the surface roughness of cathode electrodes

The objective of this paper was to analyse the effect of the surface roughness of a deposited copper cathode on repeatability for the discharge flow rate of an electroformed micro-pump. For this purpose, a measurement set-up was assembled using a glass gauge with a threshold sensor. Each test cathode was fitted into the micro-pump and the flow rate was measured three times. The value of the standard deviation of the measured flow rate was calculated as a criterion for the repeatability of the prepared micro pump. Finally, the covariance value and correlation coefficient between each surface roughness parameter and standard deviation of flow rate were calculated and compared. The results demonstrated that the Rz surface roughness parameter has the strongest relation with micro-pump flow rate repeatability using covariance analysis. Also, the auto-correlation length (ACL) that can describe the surface roughness using a correlation function has the most linear relation among all surface roughness parameters with a flow rate based on correlation analysis. SEM analysis and hydrogen bubble illustration were also reported.