Microfluidic paper-based analytical devices (μPADs) rely on capillary flow to achieve filling, mixing and delivery of liquids. We investigate the use of electroosmotic (EO) pumping as a mechanism for dynamic control of capillary flow in paper-based devices. The applied voltage can accelerate or decelerate the baseline capillary-driven velocity, as well as be used to create a tunable valve that reversibly switches the flow on and off in an electrically controlled manner. The method relies on simple fabrication and allows repeated actuation, providing a high degree of flexibility for automation of liquid delivery. We adapt the Lucas-Washburn model to account for EO pumping and provide an experimentally validated analytical model for the distance penetrated by the liquid as a function of time and the applied voltage. We show that the EO-pump can reduce filling time by 6.5-fold for channels spanning several cm in length, relative to capillary filling alone. We demonstrate the utilization of the EO-pump for a tunable and dynamic flow control that accelerates, decelerates and stops the flow on demand. Finally, we present the use of the EO-pump for fluid flow sequencing on a paper-based device.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c8lc01077c | DOI Listing |
Heliyon
January 2025
Department of Intelligent and Control Systems, Kyushu Institute of Technology, Iizuka, Fukuoka, 820-8502, Japan.
Spontaneous capillary flow in rectangular microfluidic channels is employed in microfluidic devices for various applications. The exact solution for flow in a rectangular cross-sectional channel has a complex point that contains an infinite sum term. The flow depends on the depth-width ratio of the rectangular channel's cross-section, .
View Article and Find Full Text PDFJ Neurosci Methods
January 2025
National Research Center for Sexual Medicine and Department of Urology, Inha University College of Medicine, Incheon, 22332, Republic of Korea. Electronic address:
Background: The recovery of injured peripheral nerves relies on angiogenesis, where newly formed blood vessels act as pathways guiding Schwann cells across the wound to support axon regeneration. While some research has examined this process, the specific mechanisms of angiogenesis in peripheral nerve healing remain unclear. In vitro models are vital tools to investigate these mechanisms; however, no current in vitro culture methods exist for isolating vascular cells, such as endothelial cells (ECs) and pericytes, specifically from sciatic nerves.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing Normal University, Beijing 100875, China.
Light nonaqueous-phase liquids (LNAPLs) are the main source of organic pollution in soil and groundwater environments. The capillary zone, with varying moisture contents, is the last barrier against the infiltration of LNAPL pollutants into groundwater and plays an important role in their migration and transformation. However, the effect and mechanism of the moisture content in the capillary zone on LNAPL pollutant migration are still unclear.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
With the increasing demand for improved food preservation, conventional waterproof food packaging has proven inadequate because of its limited functionality. Although incorporating features such as antibacterial and antioxidant properties into packaging enhances protection, it can compromise the hydrophobicity of the involved material, thereby increasing the risk of contamination from external sources. To address this challenge, a robust and reliable barrier capable of simultaneously integrating multiple protective functions is required.
View Article and Find Full Text PDFArterioscler Thromb Vasc Biol
January 2025
Metabolic and Immune Diseases Department, Biomedical Research Institute Sols-Morreale (IIBM), National Research Council (CSIC), Autonoma University of Madrid, Spain (T.A.-G., S.M.-T., R.C.-M., S.U.-B., S.M.-P.).
Background: Hypoxia is associated with the onset of cardiovascular diseases including cardiac hypertrophy and pulmonary hypertension. HIF2 (hypoxia-inducible factor 2) signaling in the endothelium mediates pulmonary arterial remodeling and subsequent elevation of the right ventricular systolic pressure during chronic hypoxia. Thus, novel therapeutic opportunities for pulmonary hypertension based on specific HIF2 inhibitors have been proposed.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!