Microchannels based on microelectromechanical systems (MEMS) have received a lot of interest in the microfluidics and biomedical fields over the past forty years. While their applications have been multifarious, a comprehensive literature review focusing on their design, type, and applications is not currently present in the literature. Researchers working on these elements of microchannels will gain targeted knowledge from the current review on microchannels. Due to its advanced properties, flexibility of mass, and small size, microdevice demand has been rising quickly, particularly in industrial applications. The classification of microchannels and their uses are the main focus of this work. These include but are not limited to molding, electroplating, lithography, lab-on-a-chip, micromolding, micromachining, micromilling, laser ablation, lithography, microcontact printing (µcp), hot embossing, electrochemical micromachining (EMM), and etching. In addition, numerous hybrid techniques for microchannel manufacturing have been reported. So, in essence, this review offers a range of advancements in microchannel manufacturing. The review also attempts to present a qualitative analysis describing the various methodologies associated with microchannels in terms of their design, shape, and flow regimes for applications such as pressure drop and transfer of heat prediction. Additionally, depending on the precise uses needed, a number of materials, including but not limited to ceramics, silicon, metals, and polymers, are utilized in the manufacture of microchannels. On metallic substrates, polymers such as silicon, glass, and polymeric materials are used. The biomedical industry uses polymeric and glass substrates instead of silicon substrates, which are used for mechanical engineering and electronic applications. In addition to outlining methods for choosing the best kind of microchannel, this paper also suggests important directions for the future.
Keywords: MEMS, microfluidics, microchannels, fabrication, flow characteristics.