Multicurvature viscous streaming: Flow topology and particle manipulation

Abstract

Viscous streaming refers to the rectified, steady flows that emerge when a liquid oscillates around an immersed microfeature. Relevant to microfluidics, the resulting local, strong inertial effects allow manipulation of fluid and particles effectively, within short time scales and compact footprints. Nonetheless, practically, viscous streaming has been stymied by a narrow set of achievable flow topologies, limiting scope and application. Here, by moving away from classically employed microfeatures of uniform curvature, we experimentally show how multicurvature designs, computationally obtained, give rise, instead, to rich flow repertoires. The potential utility of these flows is then illustrated in compact, robust, and tunable devices for enhanced manipulation, filtering, and separation of both synthetic and biological particles. Overall, our mixed computational/experimental approach expands the scope of viscous streaming application, with opportunities in manufacturing, environment, health, and medicine, from particle self-assembly to microplastics removal.

Oscillating viscous flow past a streamwise linear array of circular cylinders

“…2015), three-dimensional multi-curvature bodies (Bhosale et al. 2022; Chan et al. 2022), cylinder pairs with either equal (Williamson 1985; Coenen & Riley 2008; Chong et al.…”

“…Although the circular cylinder has attracted considerable attention, analyses of oscillating flows involving obstacles of differing shape are also available, including non-circular cylinders (Bearman et al 1985), spheres (Lane 1955;Riley 1966), cylindrical posts confined between parallel walls (Rallabandi et al 2015), three-dimensional multi-curvature bodies (Bhosale et al 2022;Chan et al 2022), cylinder pairs with either equal (Williamson 1985;Coenen & Riley 2008;Chong et al 2016;Coenen 2016) or unequal radii (Coenen 2013) and three-cylinder arrays in different arrangements (Chong et al 2016). Multiple circular cylinders arranged in periodic, regular lattices have also been investigated, including square arrays of identical cylinders (House, Lieu & Schwartz 2014) and square arrays involving cylinders with two different radii (Bhosale, Parthasarathy & Gazzola 2020).…”

Will microfluidics enable functionally integrated biohybrid robots?

“…In particular, the dynamism, softness, and complex morphologies of bioactuators could be used to advance flow prediction within inertial microfluidic devices ( SI Appendix ). Biohybrid robotics will raise novel questions in fundamental microfluidics (e.g., concerning inertial focusing and viscous streaming) ( 115 – 119 ) and amplify the spectrum of opportunities in applied microfluidics.…”

Three-dimensional streaming around an obstacle in a Hele-Shaw cell

“…2012; Bhosale et al. 2022). Acoustic streaming induced by surface acoustic waves has been utilized widely to enhance mixing in laminar flow in microchannels (Westerhausen et al.…”

“…Streaming flows around obstacles in micro-scale confinement are typically characterized by vortical structures and have been used widely in microfluidic applications due to their fast flow speeds, simplicity of generation, and versatility. For instance, eddies of acoustic microstreaming can be used to modify the composition of polydisperse suspensions by trapping smaller microparticles and releasing particles of larger size (Stone & Kim 2001;Beebe, Mensing & Walker 2002;Lutz, Chen & Schwartz 2003;Thameem, Rallabandi & Hilgenfeldt 2017), or to control vesicle deformation and lysis for bioengineering applications (Marmottant & Hilgenfeldt 2003;Marmottant, Biben & Hilgenfeldt 2008;Tandiono et al 2012;Bhosale et al 2022). Acoustic streaming induced by surface acoustic waves has been utilized widely to enhance mixing in laminar flow in microchannels (Westerhausen et al 2016;Ahmed et al 2019), to precisely control the intercellular distance and spatial arrangement of cells (Guo et al 2015;Mutafopulos et al 2019), and in the design of 'acoustic tweezers' that can trap suspended microparticles (Shi et al 2009;Ding et al 2012;Zhu et al 2021).…”