Sangwoo Shin

Sangwoo Shin
University at Buffalo, The State University of New York | SUNY Buffalo · Department of Mechanical and Aerospace Engineering

Ph.D.

About

89
Publications
46,092
Reads
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1,987
Citations
Citations since 2016
37 Research Items
1654 Citations
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
Introduction
Interested in transport phenomena, colloids, water treatment, energy transport/conversion, heat/mass transfer, nanomaterials, micro/nanofluidics, electrokinetics, phase-change memory, phase-change cooling...
Additional affiliations
September 2013 - December 2016
Princeton University
Position
  • PostDoc Position
March 2012 - August 2013
Yonsei University
Position
  • PostDoc Position
Education
March 2005 - February 2012
Yonsei University
Field of study
  • Mechanical Engineering
March 2001 - February 2005
Yonsei University
Field of study
  • Mechanical Engineering

Publications

Publications (89)
Article
Symbiotic bacteria often navigate complex environments before colonizing privileged sites in their host organism. Chemical gradients are known to facilitate directional taxis of these bacteria, guiding them towards their eventual destination. However, less is known about the role of physical features in shaping the path the bacteria take and defini...
Preprint
Full-text available
Symbiotic bacteria often navigate complex environments before colonizing privileged sites in their host organism. Chemical gradients are known to facilitate directional taxis of these bacteria, guiding them towards their eventual destination. However, less is known about the role of physical features in shaping the path the bacteria take and defini...
Article
Electroosmosis on non‐uniformly charged surfaces often gives rise to intriguing flow behaviors, which can be utilized in applications such as mixing processes and designing micromotors. Here, we demonstrate non‐uniform electroosmosis induced by electrochemical reactions. Water electrolysis creates pH gradients near the electrodes that cause a spati...
Article
Full-text available
The superhydrophobic surface has been used in ultradry surface applications, such as the maritime industry, windshields, non-sticky surfaces, anti-icing surfaces, self-cleaning surfaces, and so forth. However, one of the main hurdles for the production of superhydrophobic surfaces is high-cost fabrication methods. Here, we report a handy process of...
Article
From birth to health, surfactants play an essential role in our lives. Due to the importance, their environmental impacts are well understood. One of the aspects that has been extensively studied is their impact on bacteria, particularly on their motility. Here, we uncover an alternate chemotactic strategy triggered by surfactants-diffusiophoresis....
Article
In this review, we cover recent advances in microfluidic colloid separation enabled by diffusiophoresis. Diffusiophoresis describes the motion of colloidal particles induced by local chemical gradients. Despite its long history, it is only recently that diffusiophoresis has gained a renewed interest in the scientific community. Such a resurgence is...
Article
Full-text available
Correction for 'Light-triggered explosion of lipid vesicles' by Vinit Kumar Malik et al., Soft Matter, 2020, DOI: 10.1039/d0sm01027h.
Article
Lipid vesicles have received considerable interest because of their applications to in vitro reductionist cell membrane models as well as therapeutic delivery vehicles. In these contexts, the mechanical response of vesicles in nonequilibrium environments plays a key role in determining the corresponding dynamics. A common understanding of the respo...
Article
Full-text available
Merging of different streams in channel junctions represents a common mixing process that occurs in systems ranging from soda fountains and bathtub faucets to chemical plants and microfluidic devices. Here, we report a spontaneous trapping of colloidal particles in a merging flow junction when the merging streams have a salinity contrast. We show t...
Article
Full-text available
We present a microfluidic crossflow separation of colloids enabled by the dissolution of CO gas in aqueous suspensions. The dissolved CO dissociates into H+ and HCO3- ions, which are efficient candidates for electrolytic diffusiophoresis due to the fast diffusion of protons. By exposing CO2 gas to one side of a microfluidic flow channel, a crossflo...
Article
Passive targeted drug delivery to solid tumors is driven by the permeation of drug carriers through porous vasculature. Due to a dominant transport mechanism for the entry and migration of the drug carriers being diffusion, the passive drug delivery is relatively slow and ineffective in delivering large carriers to the desired location. Here, we pr...
Article
The transport of particulate matter to and from dead-end pores is difficult to achieve due to confinement effects. Diffusiophoresis is a phenomenon that results in the controlled motion of colloids along solute concentration gradients. Thus, by establishing an electrolyte concentration gradient within dead-end pores, it is possible to induce the fl...
Article
The accurate measurement of wall zeta potentials and solute--surface interaction length scales for electrolyte and non-electrolyte solutes, respectively, is critical to the design of many biomedical and microfluidic applications. We present a novel microfluidic approach using diffusioosmosis for measuring either the zeta potentials or the character...
Article
We explore the consequences of micelle formation for diffusiophoresis of charged colloidal particles in ionic surfactant concentration gradients, using a quasi-chemical association model for surfactant self assembly. The electrophoretic contribution to diffusiophoresis is determined by re-arranging the Nernst-Planck equations, and the chemiphoretic...
Article
Flows containing suspended colloidal particles and dissolved solutes are found in a multitude of natural and man-made systems including hydraulic fractures, water filtration systems and microfluidic devices, e.g. those designed for biological or medical applications. In these types of systems, unexpected particle dynamics such as rapid particle tra...
Article
Diffusiophoresis describes the motion of colloids in an electrolyte or non-electrolyte solution where there is a concentration gradient. While most of the studies of diffusiophoresis focus on the motion of solid particles, soft objects such as drops and bubbles are also known to experience diffusiophoresis. Here, we investigate the diffusiophoresis...
Article
We present a new concept of a structured surface for enhanced boiling heat transfer that is capable of self-adapting to the local thermal conditions. An array of freestanding nanoscale bimorphs, a structure that consists of two adjoining materials with a large thermal expansion mismatch, is able to deform under local temperature change. Such a surf...
Article
In boiling heat transfer, the emerging issues are the improvement of both the critical heat flux (CHF) and the thermal stability. Nanowire-forested (NF) surfaces and subcooled environments are favorable for improving CHF as well as the thermal stability owing to their distinctive morphology and consequential convection expedition, respectively. In...
Article
Many material science, coating, and manufacturing problems involve liquid films where defects that span the film thickness must be removed. Here, we study the surface-tension-driven leveling dynamics of a thin viscous film following closure of an initial hole. The dynamics of the film shape is described by a nonlinear evolution equation, for which...
Article
Removing particles from fibrous materials involves loosening via surfactants followed by particle transfer in a flow. While flow advection is commonly believed to be the major driver for pore-scale transport, small pores within the fabric do not allow any significant fluid flow inside them, thus significantly reducing the role of advection. However...
Article
Full-text available
Despite increasing acknowledgment that microorganisms underpin the healthy functioning of basically all multicellular life, few cross-disciplinary teams address the diversity and function of microbiota across organisms and ecosystems. Our newly formed consortium of junior faculty spanning fields such as ecology and geoscience to mathematics and mol...
Article
Consider the dynamics of a healing film driven by surface tension, that is, the inward spreading process of a liquid film to fill a hole. The film is modelled using the lubrication (or thin-film) approximation, which results in a fourth-order nonlinear partial differential equation. We obtain a self-similar solution describing the early-time relaxa...
Article
Full-text available
The flow of solutions containing solutes and colloidal particles in porous media is widely found in systems including underground aquifers, hydraulic fractures, estuarine or coastal habitats, water filtration systems, etc. In such systems, solute gradients occur when there is a local change in the solute concentration. While the effects of solute g...
Article
The diffusiophoretic motion of suspended colloidal particles under one-dimensional solute gradients is solved using numerical and analytical techniques. Similarity solutions are developed for the injection and withdrawal dynamics of particles into semi-infinite pores. Furthermore, a method of characteristics formulation of the diffusion-free partic...
Article
We report an experimental study on the manipulation of colloidal particles in a drop sitting on a hydrogel. The manipulation is achieved by diffusiophoresis, which describes a directed motion of particles induced by solute gradients. By letting the solute concentrations for the drop and the hydrogel be different, we control the motion of particles...
Article
The zeta potential is an electric potential in the Debye screening layer of an electrolyte, which represents a key physicochemical surface property in various fields ranging from electrochemistry to pharmaceuticals. Thus, characterizing the zeta potential is essential for many applications, but available measurement techniques are limited. Electrop...
Article
Full-text available
Water purification technologies such as microfiltration/ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating...
Article
In article number 1606040, Chang-Hwan Choi and co-workers develop a solvent exchange method that allows the full impregnation of oil into nanopores of anodized aluminum. The nanoporous oxide layer with fully and stably entrained oil shows significantly enhanced corrosion resistance and water-repellency with great durability and self-healing, which...
Article
The major drawback of current passivation techniques for preventing corrosion is the lack of ability to withstand any external damages or local defects. In this study, oil-impregnated nanoporous anodic aluminum oxide (AAO) layers are investigated to overcome such limitations and thus advance corrosion protection. By completely filling hydrophobized...
Article
Full-text available
The enhancement of boiling heat transfer, the most powerful energy-transferring technology, will lead to milestones in the development of high-efficiency, next-generation energy systems. Perceiving nano-inspired interface functionalities from their rough morphologies, we demonstrate interface-induced liquid refreshing is essential to improve heat t...
Article
We show experimentally that a flow-induced, Reynolds number-dependent particle-capture mechanism in branching junctions can be enhanced or eliminated by varying the junction angle. In addition, numerical simulations are used to show that the features responsible for this capture have the signatures of classical vortex breakdown, including an approa...
Article
A continuous and scalable bubbling system to generate functional nanodroplets dispersed in a continuous phase is proposed. Scaling up this system can be achieved by simply tuning the bubbling parameters. This new and versatile system is capable of encapsulating various functional nanomaterials to form functional nanoemulsions and nanoparticles in o...
Article
Glycerol is a viscous liquid widely used in industry and known for its strong hygroscopic nature. While this unusual property has been well documented from the perspective of solution chemistry, its impact on the mechanical properties of glycerol remains largely unknown. Here, we report a spontaneous Bénard-Marangoni instability in pure glycerol dr...
Article
Full-text available
Significance Dead-end geometries are commonly found in many porous systems. Particle transport into such dead-end pores is often important, but is difficult to achieve owing to the confinement. It is natural to expect that Brownian motion is the sole mechanism to deliver the particles into the pores, but that mechanism is, unfortunately, slow and i...
Article
Full-text available
We study the propagation of viscous gravity currents along a thin permeable substrate where slow vertical drainage is allowed from the boundary. In particular, we report the effect of this vertical fluid drainage on the second-kind self-similar solutions for the shape of the fluid–fluid interface in three contexts: (i) viscous axisymmetric gravity...
Article
Fusion between suspended lipid vesicles is difficult to achieve without membrane proteins or ions because the vesicles have extremely low equilibrium membrane tension and high poration energy. Nonetheless, vesicle fusion in the absence of mediators can also be achieved by mechanical forcing that is strong enough to induce membrane poration. Here, w...
Article
The present study investigates the effect of thermal stress on the creep lifetime for a combustion liner in a gas turbine. For the calculation of thermal stress of a combustion liner, 3D-numerical analyses are performed using an FEM commercial code. Actual operating conditions and material properties are also applied for the realistic calculation....
Article
Flow boiling accompanied impingement jet was highly desired to enhance convective heat transfer. The secondary jet impingement system was designed to get enhanced heat transfer performance. The fluidic behavior was analyzed through visualization, and the local heat transfer was evaluated using an array of resistance temperature detector (RTD) senso...
Article
Full-text available
Morphologically driven dynamic wickability is essential for determining the hydrodynamic status of solid-liquid interface. We demonstrate that the dynamic wicking can play an integral role in supplying and propagating liquid through the interface, and govern the critical heat flux (CHF) against surface dry-out during boiling heat transfer. For the...
Article
The incomplete growth of nanowires that are synthesized by template-assisted electrodeposition presents a major challenge for nanowire-based devices targeting energy and electronic applications. In template-assisted electrodeposition, the growth of nanowires in the pores of the template is complex and unstable. Here we show theoretically and experi...
Article
Exploring electrical transport in a single individual nanowire provides unique opportunities to fundamental research and practical applications in nanowire-based electronics as well as energy applications. However, measuring such electrical transport in an individual nanowire generally involves nanowire release process followed by electrode pattern...
Article
Convective boiling heat transfer is an efficient cooling mechanism to dissipate amount of thermal energy by accompanying the phase transition of the working fluids. Particularly, the amount of heat dissipation capacity can be readily extensible by increasing the degree of subcooling due to initial demands requiring for coolant saturation. Under sev...
Article
In this work, we prepared multilayered films with repeated Sb and Te layers by a thermal evaporation method. The film structure was controlled by the layer thickness ratio of Sb to Te, resulting in the formation of self-ordered superlattice structured Sb2Te2/Te films and self-ordered Sb2Te3 films. The thermoelectrical properties and the thermoelect...
Article
To obtain good properties of thermoelectric devices, low thermal conductivity and high electrical conductivity are required. But, it is difficult to control these factors individually, optimized structure is also difficult to obtain. Ordered mesoporous structure reduces the thermal conductivity. So, it can be used as thermoelectric device. In this...
Article
Full-text available
To commercialize phase change memory (PCM), a drastic change of resistivity at specific temperatures and a low power consumption to minimize heat transfer to neighboring cells are needed. Therefore, in this work, an ordered mesoporous SiO2 thin film of 45% porosity was introduced as an intercell dielectric in Ge1Sb4Te7 PCM because it has a low ther...
Article
High electrical conductivity, low thermal conductivity, and a high Seebeck coefficient are desired for thermoelectric materials. Therefore, knowledge of the relation between electrical conductivity and thermal conductivity is essential to improve thermoelectric properties. This work has focused on the synthesis of a mesoporous TiO2 and the effect o...
Article
Full-text available
The electrical and thermal conductivities and the Seebeck coefficient of mesoporous ZnO thin films were investigated to determine the change of their thermoelectric properties by controlling surfactant concentration in the mesoporous ZnO films, because the thermoelectric properties of mesoporous ZnO films can be influenced by the porosity of the me...
Article
Full-text available
We fabricated the crystallized InGaZnO thin films by sol-gel process and high-temperature annealing at 900°C. Prior to the deposition of the InGaZnO, ZnO buffer layers were also coated by sol-gel process, which was followed by thermal annealing. After the synthesis and annealing of the InGaZnO, the InGaZnO thin film on the ZnO buffer layer with pre...
Article
Full-text available
Micro-nano hybrid structure (MNHS) that comprises of microcavities and nanowires is a specific class of MNHS that is considered to be ideal for two-phase boiling heat transfer applications. Realizing MNHS with electrodeposition is favorable in boiling heat transfer, but the realization has been very difficult and time-consuming to achieve. Here, we...
Article
This article presents an application of ordered mesoporous films to phase-change memory (PCM). Though ordered mesoporous SiO2 films have attracted attention due to their regular arrangement of nanometer-sized pores, they have not yet become an integral component in any application and have not been produced in a practical manner. Also, even though...
Article
Ordered mesoporous SiO2 film has very low thermal conductivity compared to dense SiO2 film due to the presence of nanometer-sized pores. In order to apply this excellent material to thermal insulation fields, it is important to ensure the thermal stability of the pore structure at high temperature as well as thermal conductivity. In this study, ord...
Conference Paper
Artificial control of charged particles such as ions and molecules by external actions such as field-effect gating under nanofluidic environment is of critical technology for various promising applications such as protein control, DNA translocation, drug delivery, energy conversion, desalination, etc. In this regard, developing a facile method for...
Article
Short period superlattices comprising alternating InO2− and GaO+(ZnO)2 layers were fabricated by a simple hybrid solution process and reactive solid-phase epitaxy at high temperature. The epitaxial ZnO buffer layer deposited by sputtering, and an amorphous IGZO layer fabricated from a solution mixture of 1:1:1.0 (In nitrate:Ga nitrate:Zn acetate) p...
Article
Full-text available
Active modulation of ions and molecules via field-effect gating in nanofluidic channels is a crucial technology for various promising applications such as DNA sequencing, drug delivery, desalination, and energy conversion. Developing a rapid and facile fabrication method for ionic field-effect transistors (FET) over a large area may offer exciting...
Article
Thermal design is crucial in designing phase-change memory (PCM) as it is operated by thermal energy. Among the numerous factors that influence the performance of PCM, geometrical configuration is the most critical factor as the heat confinement is determined by the effective thermal resistance of the PCM cell. This study reports the thermal design...
Article
The present study investigates numerical calculations of temperature and thermal stress distributions near a normal cooling hole. A normal injection cooling hole was applied to evaluate TBC delamination using the local heat transfer data, which were obtained by the previous experiments. Experimental results were converted into the surface heat tran...
Article
Full-text available
We present an alternative route to fabricate Cu nanowires having various classes of morphologies by controlling the deposition temperature. A rough nanowire with an irregular wire diameter along the wire axis is obtained at a high deposition temperature, whereas a smooth, compact nanowire is obtained as the temperature is lowered. However, as the t...
Article
Temperature uniformity of a wafer during post-exposure bake (PEB) in lithography is an important factor in controlling critical dimension (CD) uniformity. In this study, a new hot plate system for the PEB of a 300-mm wafer was analyzed and designed. First, temperature deviation on the wafer caused by warpage was investigated, and the heater pattern...
Article
Full-text available
a b s t r a c t Ordered mesoporous oxide films have lower thermal conductivities than their corresponding dense films. In order to apply ordered mesoporous oxide films, which possess excellent properties, in various fields, it is necessary to determine their thermal insulation mechanism. In this study, we synthesized ordered and disordered mesoporo...
Article
Single-crystal InGaO 3 (ZnO) m thin films with periodic superlattice structures suitable for transparent thermoelectric applications were fabricated using a commercially available c-plane sapphire substrate, an epitaxial ZnO buffer layer, a thermal treatment at 900 °C, and an Ar plasma treatment. The introduction of the epitaxial ZnO buffer layer l...