Related Experiment Video
Updated: Jun 14, 2025

Microtensiometer for Confocal Microscopy Visualization of Dynamic Interfaces
Published on: September 9, 2022
Automatic characterization of capillary flow profile of liquid samples on μTADs based on capacitance measurement
Jie Zhou1, Haonan Li1, Xionghui Li2
1Department of Electrical Engineering, Shantou University, 243 Daxue Road, Shantou, 515063, Guangdong, China.
Abstract:
Capillary flow profile of liquid samples in porous media is closely related to the important properties of liquid samples, including the viscosity and the surface energy. Therefore, capillary flow profile can be used as an index to differentiate liquid samples with different properties. Fast and automatic characterization of capillary flow profile of liquid samples is necessary. In this work, we develop a portable and economical capacitance acquisition system (CASY) to easily obtain the capillary flow profile of liquid samples on microfluidic thread-based analytical devices (μTADs) by measuring the capacitance during the capillary flow. At first, we validate the accuracy of this method by comparing with the traditional method by video analysis in obtaining the capillary flow profiles in μTADs of cotton threads or glass fiber threads. Then we use it to differentiate liquid samples with different viscosity (mixture of water and glycerol). In addition, capillary flow profile on μTADs with chemical valves (chitosan or sucrose) can also be obtained on this device. Lastly, we show the potential of this device in measurement of hematocrit (HCT) of whole blood samples. This device can be used to catalog liquid biological samples with different properties in point-of-care diagnostics in the near future.
Related Concept Videos
Capillary Electrophoresis: Instrumentation
Electrophoresis: Overview
There...
Capillary Electrophoresis: Applications
Capillary zone electrophoresis (CZE) separates ionic components based on their electrophoretic mobility. It has been used to separate proteins, amino acids,...
Rise of Liquid in a Capillary Tube
Controlled-Current Coulometry: Overview
Capillarity in Fluid
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...

