When it comes to sweat, the first impression would be a stinky workout byproduct for most people. However, s weat is an interesting biological fluid for researchers who focus on health-assessing wearable microfluidic sensors , because it contains electrolytes, molecules, lactate, and proteins working as excellent non-invasive biomarkers of physiological health. An Overview of Microfluidics Microfluidics are small volumes of fluids, down to a quadrillionth of a liter . The behaviors of fluids are very different on the micrometric scal e compared with that in daily life , which inspires new and innovative scientific experiments. This term could refer to both studies of the fluid behaviors through micro-channels and the technology of manufacturing microminiaturized devices , in which chambers and tunnels are designed for fluids flow ing or confinement . The key concept of ...