Harvey ZambranoUniversidad Técnica Federico Santa María · Department of Mechanical Engineering
Harvey Zambrano
PhD Mechanical Eng, DTU, Denmark
About
53
Publications
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Introduction
I am a faculty (full time) in the Mechanical Eng. Dep. at USM (Chile). My research focuses on computational studies of nanoconfined flows, nanocapillarity, thermal nanomotors, solid-liquid friction at nanoscale and electrokinetic phenomena. I was a tenured assistant professor at UDEC for 5 years in the Chemical Engineering Department. Previously, I was a postdoctoral fellow at Ohio State University for 2 years conducting NEMD simulations to study transport mechanisms in nanofluidics. I obtained a PhD degree from DTU Denmark working with Prof Jens H. Walther. I am the leader and founder of the Computational Nano Lab at UDEC (now also at USM). I hold a research Professorship (part time) in the Chemical Engineering Department at UDEC (Chile).
Additional affiliations
January 2018 - present
Position
- Faculty Member
Description
- I am a faculty member in the Department of Mechanical Engineering at Universidad Técnica Federico Santa María from 2018.
January 2018 - present
Position
- Professor
Description
- I am a full time Professor and the Director of Graduate Programs in the Department of Mechanical Engineering at UTFSM. I am teaching Fluid Mechanics and conducting fundamental research on Nanoscale Fluid Dynamics.
March 2013 - March 2018
Education
January 2011 - February 2013
September 2007 - May 2011
Field of study
- Fluid Mechanics (nanofluidics and molecular simulations)
January 2007 - August 2007
Norwegian University of Science and Tech.
Field of study
- Thermal Science (Modeling of Turbulent Combustion)
Publications
Publications (53)
A comprehensive understanding of fluid dynamics of dilute electrolyte solutions in nanoconfinement is essential to develop more efficient nanofluidic devices. In nanoconduits, the electrical double layer can occupy a considerable part of the channel cross-section, therefore the transport properties of a nanoconfined electrolyte solution can be alte...
Water flow enhancement in amorphous silica nanochannels coated with monolayer graphene - Enrique Wagemann, Diego Becerra, Jens H. Walther, Harvey A. Zambrano
Devices integrated by nanoconduits hold great potential for clinical and biochemical analysis due to amplified sensibility, faster response and increased portability. In nanoconduits, wherein the electrical double layer may occupy a considerable part of the channel, the hydrodynamics of multivalent electrolytes is highly influenced by interfacial e...
Nearly frictionless water transport makes carbon nanotubes promising materials for use as conduits in nanofluidic applications. Here, we conduct Molecular Dynamics simulations of water flow within amorphous silica nanopores coated by a (39,39) Single Walled Carbon Nanotube (SWCNT). Our atomistic models describe the interaction between water and por...
Development of functional nanofluidic devices requires understanding the fundamentals of capillary driven flow in nanochannels. In this context, we conduct molecular dynamics simulations of water capillary imbibition in silica nanoslits under externally applied electric (E) fields with strengths between 0 to 1 V/nm. For increasing E-fields, we obse...
Thermophoresis is the phenomenon wherein particles experience a net drift induced by a thermal gradient. In this work, molecular dynamics simulations are conducted to study with atomistic detail the thermophoresis of water nanodroplets inside carbon nanotubes (CNTs) and its interplay with the retarding liquid-solid friction. Different applied tempe...
Transport of water in hydrophilic nanopores is of significant technological and scientific interest. Water flow through hydrophilic nanochannels is known to experience enormous hydraulic resistance. Therefore, drag reduction is essential for the development of highly efficient nanofluidic devices. In this work, we propose the use of graphitic mater...
The development of efficient nanofluidic devices requires driving mechanisms that provide controlled transport of fluids through nanoconduits. Temperature gradients have been proposed as a mechanism to drive particles, fullerenes and nanodroplets inside carbon nanotubes (CNTs). In this work, molecular dynamics (MD) simulations are conducted to stud...
Thermal Brownian Motors (TBMs) are nanoscale machines that exploit thermal fluctuations to provide useful work. We introduce a TBM-based nanopump which enables continuous water flow through a Carbon Nanotube (CNT) by imposing an axial thermal gradient along its surface. We impose spatial asymmetry along the CNT by immobilizing certain points on its...
Graphene has attracted considerable attention due to its characteristics as a 2D material and its fascinating properties, providing a potential building block for nanofabrication. In nanochannels the solid-liquid interface plays a non-negligible role in determining the fluid dynamics. Therefore, for an optimal design of nanofluidic devices, a compr...
In capillary imbibition, the classical Lucas-Washburn equation predicts a singularity as the fluid enters the channel consisting in an anomalous infinite velocity of the capillary meniscus. The Bosanquet’s equation overcomes this problem by taking into account fluid inertia predicting an initial imbibition regime with constant velocity. Nevertheles...
Carbon Nanotubes (CNTs) offer unique possibilities as fluid conduits with applications ranging from lab on a chip devices to encapsulation media for drug delivery. CNTs feature high mechanical strength, chemical and thermal stability and biocompatibility therefore they are promising candidates for nanodevice fabrication. Thermal gradients have been...
Brownian molecular motors are nanoscale machines that exploit thermal fluctuations for directional motion by employing mechanisms such as the Feynman-Smoluchowski ratchet. In this study, using Non Equilibrium Molecular Dynamics, we propose a novel thermal Brownian motor for pumping water through Carbon Nanotubes (CNTs). To achieve this we impose a...
With the emergence of the field of nanofluidics, the transport of water in hydrophilic nanopores has attracted intensive research due to its many promising applications. Experiments and simulations have found that flow resistance in hydrophilic nanochannels is much higher than those in macrochannels. Indeed, this might be attributed to significant...
Nanoscale capillarity has been extensively investigated, nevertheless many fundamental questions remain open. In spontaneous imbibition, the classical Lucas-Washburn equation predicts a singularity as the fluid enters the channel consisting in an anomalous infinite velocity of the capillary meniscus. The Bosanquet's equation overcomes this problem...
Electrokinetic transport of aqueous electrolyte solutions in nanochannels and nanopores is considered
important toward the understanding of fundamental ion transport in many biological systems, lab-on-chip, and organ-on chip devices. Despite the overall importance of these systems and devices, detailed calculations showing velocity and concentratio...
Electroosmotic flow in a silica slit channel with nonuniform surface charge density is investigated. In nanoconfinement, the electrical double layer occupies a non-negligible fraction of the system. Therefore, modifying the charge density on specific locations on the channel wall surface allows effective manipulation of the electroosmotic flow rate...
The characteristic high surface area to volume ratio causes ionic transport in nanofluidic devices to be governed by surface properties like surface charge. In recent years, experimental demonstrations have shown gate electrodes embedded in the nanochannel wall to systematically alter the surface potential to manipulate ionic transport in nanochann...
In this study, a novel concept of nanoscale pump fabricated using Carbon Nanotubes (CNTs) is presented. The development of nanofluidic systems provides unprecedented possibilities for the control of biology and chemistry at the molecular level with potential applications in low energy cost devices, novel medical tools, and a new generation of senso...
The transport of water in nanopores is of both fundamental and practical interest. Graphene Channels (GCs) are potential building blocks for nanofluidic devices due to their molecularly smooth walls and exceptional mechanical properties. Numerous studies have found a significant flow rate enhancement, defined as the ratio of the computed flow rate...
Nanofluidic devices such as Lab-On-a-Chip often are designed to transport water solutions through hydrophilic nano-conduits. In these systems with narrow confinement, the viscous forces dominate the flow and as a result, the hydrodynamic friction drag is very high. Moreover, the drag and the amount of energy required for pumping a fluid are directl...
Molecular dynamics simulations are conducted to investigate the initial stages of spontaneous imbibition of water in slit silica nanochannels surrounded by air. An analysis is performed of the effects of nanoscopic confinement, initial conditions of liquid uptake and air pressurization on the dynamics of capillary filling. The results indicate that...
The transport of aqueous solutions in artificial nanopores is of both fundamental and technological interest. Recently, carbon nano-structured materials (fullerenes) have attracted a great deal of attention in nanotechnology. In fact, due to their large specific surface area, high thermal conductivity, extremely low surface friction and superior me...
Capillarity is currently subject to a significant research interest. Attention is mainly paid to the late stage of the imbibition when a developed flow is reached and the Laplace pressure is balanced by the viscosity. Nevertheless, as the miniaturization of devices is reaching the nanoscale a thorough understanding of fluid flow in nanoconfinement...
As a silica surface is exposed to an electrolyte, a net charge arise on the solid-liquid interface. In a confined electrolyte, a consequence of the net charged interface is the development of an imbalance of ions near the confining walls. The net charged region near the walls is called the Electrical Double Layer (EDL). A critical technology for th...
In this paper we present a new force field suitable for performing molecular dynamics simulations of amorphous silica and water at different air pressures. We calibrate the interactions of each specie presents in the system using dedicated criteria such as the contact angle of a water droplet on a silica surface and the gas solubility in water at d...
Capillarity is a classical topic in fluid dynamics. The fundamental relationship between capillarity and surface tension is solidly established. Nevertheless, capillarity is an active research area especially as the miniaturization of devices is reaching the molecular scale. Currently, with the fabrication of microsystems integrated by nanochannels...
In this work, we study electroosmosis in a multivalent electrolyte solution. Specifically,
we study the response of an electroosmotic system as the concentration of a divalent cation
is varied in a water solution of sodium chloride confined in a nanochannel and as axial
electric fields are applied to the system. It has been observed in recent exper...
The advancement of micro-total analysis systems is increasing the ability to perform multiple functions in one microfluidic device. These systems have several advantages in biomedical applications, including lower equipment and personnel costs, reduced power requirements, faster separations, and smaller sample and reagent volume requirements. Becau...
The controlling of the Electroosmotic flow (EOF) in nanoconfinement is important in several nano and
bio technology applications. In this work, the Electroosmotic flow (EOF) is studied by conducting
Non-Equilibrium MD Simulations (NEMDS) of an electrolyte confined in a nanochannel. The silica
channel is 34.76 x 2.53 x 7.0 nm. We model a very long c...
A critical enabling technology for the next generation of nanodevices, such as nanoscale lab on a chip
systems, is controlling the Electroosmotic Flow (EOF) in nanochannels. In electrokinetic driven flows
in nanochannels an external applied electric field (E) parallel to the channel walls drives the
counterions and liquid molecules in the EDL. Beca...
This paper reports on simulations of electroki-netic transport in an electrolyte nanofilm in contact with a negatively charged substrate with discontinuous counter-charged patches. All-atom molecular dynamics simulations of an aqueous solution of chloride placed on a silica slab were conducted. The response of the system is investigated as it is su...
A comprehensive understanding of the transport of biomedical cells in microchannels is of great importance for the development of fluidic devices for novel bio-diagnosis techniques such as cell labeling and sorting processes in cancer diagnosis research. In this paper mathematical models and computational simulations to describe the transport of ce...
The objective of the present paper is to review the fundamental theory of the motion of a collection of colloidal particles near solid walls and to compare theoretical computations with the experiments conducted by Kazoe and Yoda1 for electroosmotic flow. Under-standing the near-wall transport of suspended particles is also relevant to a number of...
In electroosmotic transport (EOT), particle mobility results not only from the dragging exerted by the electrolyte, but also from the force exerted by the External Electric Field (EEF), and from the interactions with the walls and with the solvent. The objective of this work is to develop a unified theory of the motion of colloidal particles near w...
We study Electroosmotic flow (EOF) by conducting Non-Equilibrium MD Simulations (NEMDS) of water and chloride on a silica substrate. The system response is studied as axial electric fields (AEF) are imposed and as the surface charge (SC) is modified by implementing counter-charged patches (CP). The density profiles reveal that the CP result in an i...
This paper reports on atomistic and continuun simulations of electrokinetic
transport in a water-chloride nanofilm in contact with the surface of a negatively charged silica
substrate with discontinuous counter-charged patches. All-atoms non-equilibrium molecular dynamics
simulations of a system containing an aqueous solution of chloride (0.55M)...
We conduct molecular dynamics simulations of a molecular linear motor consisting of coaxial carbon nanotubes with a long outer carbon nanotube confining and guiding the motion of an inner short, capsulelike nanotube. The simulations indicate that the motion of the capsule can be controlled by thermophoretic forces induced by thermal gradients. The...
Molecular Dynamics of a Linear Nanomotor Driven by Thermophoresis
Harvey A. Zambrano, Jens H. Walther and Richard L. Jaffe
Department of Mechanical Engineering, Fluid Mechanics, Technical University of Denmark, DK-2800 Lyngby, Denmark; Computational Science and Engineering Laboratory, ETH Zurich, CH-8092, Switzerland and NASA Ames Research Center...
Wetting is essential and ubiquitous in a variety of natural and technological
processes. Silicon dioxides-water systems are abundant in nature and play fundamental roles in a diversity of novel science and engineering activities such as silicon based devices, nanoscale lab on a chip systems and DNA microarrays technologies. Although extensive exper...
We study the thermophoretic motion of water nanodroplets confined inside carbon nanotubes using molecular dynamics simulations. We find that the nanodroplets move in the direction opposite the imposed thermal gradient with a terminal velocity that is linearly proportional to the gradient. The translational motion is associated with a solid body rot...
Los cinco criterios, veinte indicadores y se-senta probables verificables establecidos en el sistema de criterios e indicadores propues-to para la aplicación del enfoque ecosistémico en Colombia se aplicaron en el estudio "Eva-luación integrada del Darién colombiano". En el caso del criterio Mantenimiento de la inte-gridad del ecosistema, fue posib...
Projects
Projects (5)
Advances in nanofabrication are allowing miniaturization of Lab-On-a-Chip (LOC) units toward functional nanofluidic systems. The functionality of these multistage systems relies on the efficient transport of water solutions through nanopores integrating their active components. In such conduits, the extremely high surface to volume ratio leads to an augmented effect of the interfacial properties on the bulk of the fluid. As a result, the interfacial properties signficantly increase the viscous friction reducing flow capacity. In the present study, performing atomistic simulations, we show that significant drag reduction can be achieved in a polyamide nanoslit pore by using graphene and hBN as wall coatings. The insights reported in this study may serve as a guide in designing strategies to achieve low friction transport of water solutions in nanostructured pores.
We conduct molecular simulations of water filling channels of amorphous silicon dioxide in presence of air at different pressures. We focus our investigation on the initial stage of the capillary filling process to reveal the origin of the divergence between classical theory (Lucas-Washburn-Bosanquet) and experimental measurements. Moreover, we investigate the effects on water imbibition process of external electric fields, surface roughness, temperature variation and formation of the meniscus at initial stages of capillary filling.
