Notes of the course micro scales part

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Bioartificial systems at the micro scale Intro Definitions: - Miniaturization: the process of making small things, including reduction in size of things that exist on a larger scale and fabrication of small things whose big counterparts do not exist. - Small: defined as the size of something that is small with respect to humans, something that cannot be easily handled with our fingers and whose details cannot be easily seen with the naked eye, anything smaller than about a millimetre. - Bioartificial: comprise living systems and materials, we will consider bioMEMS, they have both electro and mechanical functions BioMEMS: stands for micro-electro-mechanical systems, any biomedical device that is fabricated using any miniaturization technique. By derivation, BioMEMS is also the engineering field that uses or develops them - In vitro: o Point of care diagnosis o High throughput devices: such as DNA microarrays o Cell culture and cell sorting - In vivo: implantable systems Advantages of bioMEMS: - Small dimensions: o Scale: devices have the same scale of cells o Portability: decreasing the size decreases also the power needed by the system o Reduces reagents costs Examples: exploiting microscale physics increases the control. In a microfluidic device usually Re=2, but it can be <1, so at the microfluidic scale the flow is laminar. Turbulent flow corresponds to With such a high pressure the device would be destroyed, so turbulent flow is never achieved. In laminar flows two combined steams continue to flow parallel to one another. - High throughput: o we can increase the number of operations running in parallel o complex fluidic control o batch fabrication reduces costs Examples: o high throughput screening HTS: in drug companies to screen all the substances contained in…