Figure 1 - uploaded by Sankar Raju Narayanasamy
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An overview of WJ micronozzle (A and B) Internal view of the WJ micronozzle during operation (A) and outside view of the gas focused self-sequencing WJ observed at 0.5 bar applied gas pressure and 66 mL/s liquid flow rate (B) A perpendicular illustrating the 2D aspect of the droplet fan can be found in Figure S3. (C) Schematic representation of the WJ from a high-aspect-ratio WJ micronozzle. (D) Nozzle design parameters (left, see Table S1 for details), scanning electron microscopic image of polydimethylsiloxane (PDMS) nozzle (middle), and the high-aspect-ratio nozzle outlet (right).
Source publication
Well-defined aerosols pave the way for versatile basic and applied research. Here, we demonstrate a unique whipping instability that generates from a high-aspect-ratio microfluidic device resulting in a unique steady-state gas-focused whipping jet (WJ) without any need for electrification. This WJ device emanates a multi-monodisperse whipping spray...
Contexts in source publication
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... we describe a new gas-focused whipping jet (WJ) microfluidic device to address these limitations that could emanate a novel multi-monodisperse whipping spray jet with a 2D profile with a similar nozzle operation as that of a gas-focused microfluidic nozzle. 2 The principal design and operation of this microfluidic device is shown in Figure 1 and is further described below and in Note S2. Here, we report our analytic derivation that predicts the whipping behavior of our new anisotropic microfluidic liquid jet device. ...
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... this study, we investigate the whipping behavior of an anisotropic microfluidic liquid jet device. This device is based on our previous polydimethylsiloxane (PDMS) gas dynamic virtual nozzle design, 2 but it features a higher PDMS central layer with 300 mm height (see Figure 1) and, hence, a rectangular/anisotropic structure. Unlike the commonly reported WJ devices, which typically emit a 3D cone pattern, 26,39 our WJ device produces a unique pattern of well-sorted, uniformly distributed, and 2D spray patterns (Figure 1). ...
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... device is based on our previous polydimethylsiloxane (PDMS) gas dynamic virtual nozzle design, 2 but it features a higher PDMS central layer with 300 mm height (see Figure 1) and, hence, a rectangular/anisotropic structure. Unlike the commonly reported WJ devices, which typically emit a 3D cone pattern, 26,39 our WJ device produces a unique pattern of well-sorted, uniformly distributed, and 2D spray patterns (Figure 1). An additional orthogonal view highlighting the 2D nature of the spray pattern can be found in Figure S3. ...
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... the evolution of lateral (m = 1) perturbations is a result of the competition between the destabilizing aerodynamic pressure r l (v 2 Àv 1 ) 2 associated with the slip velocity (v 2 Àv 1 ) and the restoring capillary stress due to the surface tension s. In the WJ device, a meniscus is formed at the exit of the main channel ( Figure S1) by the flow-focusing gas stream ( Figure 2A). The meniscus radius can be defined by the characteristic length (e), which depends on the shear tension stress. ...
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... 7 is used for calculating jet diameters in Figures 3B and 3C using a combination of literature values for the used fluids and experimentally fitted parameters (using Fiji, image processing package) as shown in Table S1. For a given scaling of WJ geometry, the semi-empirical equation of the spreading angle of WJ (q) can be written as (see supplemental information for derivation; Note S4) As shown above in Equation 8, the spreading angle (q) is a function of the ratio of critical jet flow rate (Q critical ) to the jet flow rate (Q) and the dimensions, i.e., width of the main channel (r i ), width of the outlet (r o ), and the central layer height device (h) (see Figure S1). ...
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... master mold fabrication process was started by spin coating a 3" silicon wafer with a negative photoresist (SU-8 2050, Microchem Co, USA). The designs ( Figure S1 A, B and C) were exposed under vacuum contact mode using a MJB4 mask aligner (Suss Micro Tech, Germany) in a sequence as outlined before. 1,2 In short, a sequences of layers was spin-coated and exposed using the steps outlined below to create two mold halves; one with the layers A+B+C, and one with the layers B+C. ...
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... activated device halves were aligned under a microscope and bound in an oven overnight at 45 0 C as shown in Figure S1. SEM images of nozzle outlet with high aspect ratios are shown in Figure S1. ...
