Microchannel (microtechnology)

Microchannel in microtechnology is a channel with a hydraulic diameter below 1 mm, usually 1–99 μm.^[1] Microchannels are used in fluid control (see Microfluidics), heat transfer (see Micro heat exchanger) and cell migration observation.^[2] They are more efficient than their 'macro' counterparts, because of a high surface-area to volume ratio yet pose a multitude of challenges due to their small size.^[3]

Depiction of a cell passing through a microchannel

This article is about small-sized liquid ducts. For a computer bus, see Micro Channel architecture.

Materials

Different types of materials are required for the different uses of microchannels. These are the three main categories.^[4]

Polymeric and glass substrates

Polymethyl methacrylate (PMMA) is used as a solution to a wide range of microfluidic devices due to its low cost and easier fabricating methods.^[4] Silicon elastomers can be used for situations in which elasticity and deformation is necessary.^[5]

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.^[4][6]

Semiconductors, ceramics and composites

Ceramic materials allow for high-temperature operation in comparison to metallic substrates and enable operation in harsh chemical environments in which metals cannot be used.^[7]

History

The concept of the microchannel was proposed for the first time by researchers Tuckerman and Pease of Stanford Electronics Laboratories in 1981.^[8] They suggested an effective method for designing microchannels in the laminar and fully developed flow.^[9]

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.^[10]

See also

• Micro process engineering
• Microreactor