Whitepaper on the measurement of hydrophobicity, hydrophilicity, and wettability

This whitepaper is written to provide information and procedures to test the hydrophobicity, hydrophilicity, and wettability, focused on microfluidic device applications. The methods used ensure traceability to national standards and conformity to existing normative standards.

Microfluidics, concerned with fluid-handling in the nano-to-millilitre scale, has major applications in biomedical and chemical analysis. At these small scales surface tension forces play a major role in fluid dynamics and therefore must be understood by microfluidics engineers and scientists.   Surface tension forces are influenced by surface properties like texture, surface energy etc. and result in specific interaction of liquid and surface. Understanding that interaction is key to understand microfluidic flow properties as resistivity and fouling, i.e., key performance parameters of microfluidic devices. The interaction is generally expressed as hydrophobicity, hydrophilicity, and wettability. Efficient and correct measurement of these quantities is therefore needed.