Microchannel in

microtechnology Microtechnology deals with technology whose features have dimensions of the order of one micrometre (one millionth of a metre, or 10−6 metre, or 1μm). It focuses on physical and chemical processes as well as the production or manipulation of str ...

is a channel with a

hydraulic diameter The hydraulic diameter, , is a commonly used term when handling flow in non-circular tubes and channels. Using this term, one can calculate many things in the same way as for a round tube. When the cross-section is uniform along the tube or channel ...

below 1 mm, usually 1–99 μm. Microchannels are used in fluid control (see

Microfluidics Microfluidics refers to the behavior, precise control, and manipulation of fluids that are geometrically constrained to a small scale (typically sub-millimeter) at which surface forces dominate volumetric forces. It is a multidisciplinary field tha ...

), heat transfer (see

Micro heat exchanger Micro heat exchangers, Micro-scale heat exchangers, or microstructured heat exchangers are heat exchangers in which (at least one) fluid flows in lateral confinements with typical dimensions below 1 mm. The most typical such confinement are mi ...

) and

cell migration Cell migration is a central process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular dire ...

observation. They are more efficient than their 'marco' counterparts, because of a high surface-area to volume ratio yet pose a multitude of challenges due to their small size.

Materials

Different types of materials are required for the different uses of microchannels. These are the three main categories.

Polymeric and glass substrates

polymethyl methacrylate Poly(methyl methacrylate) (PMMA) belongs to a group of materials called engineering plastics. It is a transparent thermoplastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and brands Crylux, Plexiglas, Acrylite, ...

(PMMA) is used as a solution to a wide range of microfluidic devices due to its low cost and easier fabricating methods. Silicon elastomers can be used for situations in which elasticity and deformation is necessary.

Metallic substrates

Metallic substrates are often chosen for their advantageous metallic properties, such as withstanding high temperatures and transferring heat faster. They can be subject to

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

Semiconductors, ceramics and composites

Ceramic materials allow for high-temperature operation in comparison to metallic substrates and enable operation in harsh chemical environments in zhich metals cannot be used.

History

The concept of the microchannel was proposed for the first time by researchers Tuckerman and Pease of Stanford Electronics Laboratories in 1981. They suggested an effective method for designing microchannels in the laminar and fully developed flow.

Common uses

Microchannels are extensively used in the pharmaceuticals, and biochemical industries due to short diffusion distances, higher interfacial area, and higher heat/mass transfer rates.Jaiswal, P., Kumar, U., Biswas, K. G.(2021) Liquid-Liquid Flow through Micro Dimensional Reactors: A Review on Hydrodynamics, Mass Transfer, and Reaction Kinetics. Exp. Comput. Multiph. Flow 2021. https://doi.org/10.1007/s42757-020-0092-0

Sources

* Microtechnology Microfluidics {{tech-stub