Microchannel (microtechnology)
{{Short description|Basic structure used in microtechnology}}
File:Cell in a microchannel.png
{{About|small-sized liquid ducts|a computer bus|Micro Channel architecture}}
Microchannel in microtechnology is a channel with a hydraulic diameter below 1 mm, usually 1–99 μm.{{cite book |last=Kandlikar |first=Satish G. |url=https://archive.org/details/heattransferflui00kand |title=Heat transfer and fluid flow in minichannels and microchannels |publisher=Elsevier B.V. |year=2006 |isbn=978-0-08-044527-4 |location=Amsterdam, the Netherlands |pages=[https://archive.org/details/heattransferflui00kand/page/n472 450] |url-access=limited}} Microchannels are used in fluid control (see Microfluidics), heat transfer (see Micro heat exchanger) and cell migration observation.{{Cite web |title=Microchannels |url=https://www.4dcell.com/cell-culture-systems/microchannels/ |access-date=2022-07-15 |website=4Dcell |language=en-US}} 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.{{Cite web |last=Puccio |first=Kris |date=2020-02-10 |title=Understanding Microchannel Heat Exchangers & Their Use Cases |url=https://www.therma.com/microchannel-heat-exchangers/ |access-date=2022-07-15 |website=Therma |language=en-US}}
Materials
Different types of materials are required for the different uses of microchannels. These are the three main categories.{{Cite journal |last1=Prakash |first1=Shashi |last2=Kumar |first2=Subrata |title=Fabrication of microchannels: A review |url=https://www.researchgate.net/publication/280923796 |journal=Journal of Engineering Manufacture |volume=229|issue=8 }}
= 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. Silicon elastomers can be used for situations in which elasticity and deformation is necessary.{{Cite journal |last1=Yuen |first1=Michelle |last2=Kramer |first2=Rebecca |title=Fabricating microchannels in elastomer substrates for stretchable electronics |url=https://www.eng.yale.edu/faboratory/publications/conference/2016/Yuen%20and%20Kramer%20-%202016%20-%20Fabricating%20Microchannels%20in%20Elastomer%20Substrates%20for%20Stretchable%20Electronics.pdf |journal=MSEC Science}}
= 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.{{Citation |last1=Andou |first1=F. |title=MICROCHANNEL ARRAY CREATION BY MEANS OF ULTRAPRECISION MACHINING |date=2007-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9780080449630500345 |work=Mechatronics for Safety, Security and Dependability in a New Era |pages=163–168 |editor-last=Arai |editor-first=Eiji |place=Oxford |publisher=Elsevier |language=en |isbn=978-0-08-044963-0 |access-date=2022-07-15 |last2=Yamamoto |first2=A. |last3=Kawai |first3=T. |last4=Ohmori |first4=H. |last5=Ishida |first5=T. |last6=Takeuchi |first6=Y. |editor2-last=Arai |editor2-first=Tatsuo}}
= 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.{{Cite journal |last1=Kee |first1=Robert J. |last2=Almand |first2=Berkeley B. |last3=Blasi |first3=Justin M. |last4=Rosen |first4=Benjamin L. |last5=Hartmann |first5=Marco |last6=Sullivan |first6=Neal P. |last7=Zhu |first7=Huayang |last8=Manerbino |first8=Anthony R. |last9=Menzer |first9=Sophie |last10=Coors |first10=W. Grover |last11=Martin |first11=Jerry L. |date=2011-08-01 |title=The design, fabrication, and evaluation of a ceramic counter-flow microchannel heat exchanger |url=https://www.sciencedirect.com/science/article/pii/S1359431111001414 |journal=Applied Thermal Engineering |language=en |volume=31 |issue=11 |pages=2004–2012 |doi=10.1016/j.applthermaleng.2011.03.009 |bibcode=2011AppTE..31.2004K |issn=1359-4311|url-access=subscription }}
History
The concept of the microchannel was proposed for the first time by researchers Tuckerman and Pease of Stanford Electronics Laboratories in 1981.Tuckerman, D. B., & Pease, R. F. W. (1981). High-performance heat sinking for VLSI. IEEE Electron device letters, 2(5), 126-129. https://dx.doi.org/10.1109/EDL.1981.25367 They suggested an effective method for designing microchannels in the laminar and fully developed flow.Salimpour, M. R., Al-Sammarraie, A. T., Forouzandeh, A., & Farzaneh, M. (2019). Constructal design of circular multilayer microchannel heat sinks. Journal of Thermal Science and Engineering Applications, 11(1), 011001. https://dx.doi.org/10.1115/1.4041196
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