Gaining predictive power for porous media pumps
Gaining predictive power for porous media pumps lead image
If air is removed from the pores of porous media, these materials will reabsorb the surrounding air, transforming into a suction pump. Self-powered, portable porous media pumps are used to precisely move liquids through microfluidic channels in various applications, including the study of microreactors, disease, and drug testing.
Benavent-Claró et al. developed a theoretical model that can predict the behavior of a liquid moved by a porous media pump. This universal equation, which holds across all porous materials, fluid types, and microfluidic channel geometries, will allow researchers to tailor these pumps for different applications.
“This work provides a powerful predictive tool for designing different fluidic pumps using
various porous materials,” said author Andreu Benavent-Claró. “Engineers and researchers can use our model to select or design porous structures that are optimized for specific flow rates and applications. This opens exciting possibilities in disease detection, organ-on-a-chip systems, drug delivery, and chemical analysis.”
To test the model, the authors conducted experiments with polydimethylsiloxane (PDMS) — the most common material used as a porous media pump — and water. They found the data matched well with the theory. These experiments also showed that coating the PDMS pump with a non-porous layer prevents it from absorbing outside air, improving its efficiency. The authors extended the model to capture this effect, and plan to expand it further.
“Next, we aim to create a direct correlation between the porosity properties of the material and
the characteristic timescale of the fluid dynamics,” Benavent-Claró said. “This will allow researchers to choose the type of equipment that best suits their needs.”
Source: “Mathematical model of fluid front dynamics driven by porous media pumps,” by Andreu Benavent-Claró, Yara Alvarez-Braña, Fernando Benito-Lopez, Lourdes Basabe-Desmonts, and Aurora Hernandez-Machado, Physics of Fluids (2025). The article can be accessed at https://doi.org/10.1063/5.0252721 .
