(Rems et al. 2016). In addition, a deeper understanding of fluid flow, mass of heat

transfer, electrokinetics, electrochemistry, and molecular biology becomes manda-

tory in the designing of micro- and nano-devices.

Microfluidics deals with the systems which process minimal quantities of fluids

through channels with microscale dimensions—ranging from 10 μm to 100 μm.

Their properties result in very useful applications in varied fields which include

biology, chemistry, information technology, optics, and many more. It not only

saves money but also enormous time expended in research.

Study of behavior, manipulation, and control of fluids confined to nanostructures

(1–100 nm) is termed as nanofluidics (Eijkel and van den Berg 2005). Fluids

confined to nano-structures exhibit distinctive physical parameters for a truly valid

reason that the magnitude of their dimensions is of the same order as that of its

characteristic’s physical scaling length (e.g., Debye length, hydrodynamic radius,

etc.). As the dimensions of nanostructure correspond to molecular scaling lengths,

the physical constraint results in new properties not observed in bulk.

Enormous increment is observed in viscosity in proximity of the pore wall

affecting its thermodynamic properties as well as chemical reactivity at the fluid-

solid interface. For example, in nano-capillary array membrane (NCAM) (Joshi et al.

2021), surface charges start playing a dominant role at the electrified interface.

Figure 16.5 displays one such NCAM which consists of parallel nanocapillaries

each with pore radius, a/2, ~Debye length, κ
¹. The Debye length is a characteristic

distance over which ions and electrons can be separated in a plasma and is a ratio of

electron thermal velocity divided by the plasma frequency. Significant applications

of nanofluidics lie in its potential to integrate into the microfluidic system resulting in

lab-on-a-chip devices such as PCR which could be employed as analytical systems.

When integrated with microfluidic devices, NCAMS could be advantageously used

as a digital switch to transfer fluids between one microfluidic channel to another,

proficiently segregate and relocate the analytes on the basis of size and mass, mix

reactants, and separate out characteristically dissimilar fluids. A natural analogue of

fluid-handling capabilities of these nanofluidic structures could be found in

Fig. 16.4 Coronary artery disease: angina and heart attack

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Role of Microfluidics and Nanofluidics in Managing CAD

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