Paper Porosity Measurement by Electric Current

Abstract

In this research we measured the electric current in a paper channel to estimate the porosity of paper When ions flow in a paper channel the fibers in the paper obstruct the flow Therefore channels with fibers have lower flux and lower current because the volumetric flow rate in a paper channel with fibers is lower than that of a hollow channel (without fibers) Based on this concept we conducted the following study In order to reduce the evaporation effect and create the same channel surface we used two pieces of polydimethylsiloxane (PDMS) to sandwich the paper channel and fixed them together with double-sided tape In addition we changed the applied voltage solution and the size of the channels to analyze the experimental results under different conditions It was found from the experimental results that the measured porosity of the paper wasn’t changed significantly at different applied voltages Therefore this method can be carried out at a low voltage Similar results can be obtained using potassium chloride (KCl) and sodium chloride (NaCl) to measure the porosity of paper This infers that a strong electrolyte can be used in this method Changing the size of the channels didn’t affect the experiment results so a lower volume of paper can be used to measure porosity This research offers a new method to measure the porosity of paper This method can serve as a reference when choosing the material for use in microfluidic paper-based devices (μPADs)

Date of Award	2016 Aug 23
Original language	English
Supervisor	Ruey-Jen Yang (Supervisor)