Particulate Cake Formation and Pressure Development in Microfluidic Membrane Filters

In filtering applications, particulates build up on the filtering membrane, forming a cake layer that directly affects permeability and increases pressure across the filter. In this investigation, 10 µm microchannels were fabricated using photolithography to create filters with porosities that vary between 9% and 23%. To estimate cake layer growth, a water–glycerol solution containing a 1% volume fraction of 15 µm polystyrene particles was injected by a syringe pump into filtration media at 300, 500 and 700 µL h−1 flow rates for 300 s. A differential pressure sensor was mounted across the inlet and outlet channels to measure transmembrane pressure (TMP) over time. It was found that higher flow rates accelerate particle deposition on the membrane surface, which contributes to a larger cake area and a corresponding rise in TMP. These findings will give valuable insights into clogging dynamics to optimize the filter’s efficiency and lifespan.