Microfluidic devices are used to control and study fluids at the microscale. These devices can be used to manipulate, mix, or monitor small volumes of fluid, and are often used in biomedical applications such as blood tests and cell culture. Microfluidic devices usually consist of a network of channels and chambers etched into a substrate, often made of glass or silicon. The dimensions of these channels are typically on the order of micrometers (µm), and they can be further subdivided into nanochannels with dimensions in the range of tens to hundreds of nanometers.
The fluid flow in microfluidic devices is typically laminar, meaning that the fluid flows in parallel layers with no mixing between layers. This allows for very precise control over the flow rate and direction of fluid flow. In addition, because the channels are so small, viscous forces dominate over inertial forces, which results in low-speed but steady flow. The resulting slow flow rates allow for more time for chemical reactions to occur within the device.
One advantage of using microfluidic devices is that they can be easily integrated with other microelectronic components. For example, sensors and actuators can be placed directly on or near the device to monitor or control fluid flow. This integration allows for miniaturization of complete systems while maintaining high levels of functionality. Additionally, because all components are placed close together, there is a reduction in errors due to misalignment or crosstalk between different parts of the system.
Microfluidic devices have been used for a variety applications including blood tests, cell culture studies, drug delivery systems, and chemical analysis instruments. In general, these devices offer advantages over traditional methods due to their small size (allowing for easy integration with other electronics), precise control over fluid flow rates (enabling delicate experiments), and low cost (due to batch fabrication techniques).