Tengfei Luo

Tengfei Luo
University of Notre Dame | ND · Department of Aerospace and Mechanical Engineering (AME)

About

187
Publications
44,740
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
6,152
Citations

Publications

Publications (187)
Article
Understanding interfacial thermal transport between lithiated two-dimensional materials and polymers can provide useful guidelines to design thermally tunable and conductive composites for efficient thermal management of energy systems. In this work, molecular dynamics simulations are conducted to investigate the effect of lithium (Li)-ion intercal...
Article
Graphene nanochannels and nanostructures have been of great interest to applications like nanofluidics and solar-thermal evaporation since nanoconfinement can lead to altered liquid properties. In this article, we employ molecular dynamics simulations combined with the free energy perturbation method to study the influence of external electric fiel...
Article
Solar steam generation can be affected by many external factors such as applied electric fields. The evaporation of water under uniform and time-varying electric fields have been widely investigated in both experimental and theoretical work. However, the effect of spatially gradient electric fields on water evaporation remains unknown. In this work...
Article
Full-text available
Plasma-enhanced chemical vapor deposition (PECVD) provides a low-temperature, highly-efficient, and catalyst-free route to fabricate graphene materials by virtue of the unique properties of plasma. In this paper, we conduct reactive molecular dynamics simulations to theoretically study the detailed growth process of graphene by PECVD at the atomic...
Article
The light switchable thermal conductivity displayed by some polymers makes them promising for applications like data storage, temperature regulation and light switchable devices. In this study, the mechanism of thermal conductivity switching in poly[6-(4-phenyldiazenyl phenoxy)hexyl metharylate] is studied using molecular dynamics (MD) simulations....
Article
Atomic vibrations influence a variety of phenomena in solids and molecules, ranging from thermal transport to chemical reactions. These vibrations can be decomposed into normal modes, often known as phonons, which are collective motions of atoms vibrating at certain frequencies; this provides a rigorous basis for understanding atomic motion and its...
Article
Full-text available
Phonon Boltzmann transport equation (BTE) is a key tool for modeling multiscale phonon transport, which is critical to the thermal management of miniaturized integrated circuits, but assumptions about the system temperatures (i.e., small temperature gradients) are usually made to ensure that it is computationally tractable. To include the effects o...
Preprint
Full-text available
The ability to separate miniscule solid particles (e.g., nanoparticles, NPs) from liquid is important to a wide range of applications, such as water purification, material deposition, and biomedical engineering. Such separation is usually achieved by displacing liquid via filtration or distillation. However, directly moving small particles out of l...
Preprint
Phonon Boltzmann transport equation (BTE) is a key tool for modeling multiscale phonon transport, which is critical to the thermal management of miniaturized integrated circuits, but assumptions about the system temperatures (i.e., small temperature gradients) are usually made to ensure that it is computationally tractable. To include the effects o...
Article
Marine oil contamination remediation remains a worldwide challenge. Siphon action provides a spontaneous, continuous, low-cost and green route for oil recovery. However, it is still limited by the low oil...
Preprint
Full-text available
Developing amorphous polymers with desirable thermal conductivity has significant implications, as they are ubiquitous in applications where thermal transport is critical. Conventional Edisonian approaches are slow and without guarantee of success in material development. In this work, using a reinforcement learning scheme, we design polymers with...
Preprint
Full-text available
Developing amorphous polymers with desirable thermal conductivity has significant implications, as they are ubiquitous in applications where thermal transport is critical. Conventional Edisonian approaches are slow and without guarantee of success in material development. In this work, using a reinforcement learning scheme, we design polymers with...
Article
Full-text available
Interfaces impede heat flow in micro/nanostructured systems. Conventional theories for interfacial thermal transport were derived based on bulk phonon properties of the materials making up the interface without explicitly considering the atomistic interfacial details, which are found critical to correctly describing thermal boundary conductance. Re...
Article
Full-text available
A pulling motion of supercavitating plasmonic nanoparticle (NP) by a single plane wave has received attention for the fundamental physics and potential applications in various fields ( e.g. , bio-applications, nanofabrication, and nanorobotics). Here, the supercavitating NP depicts a state where a nanobubble encapsulates the NP, which can be formed...
Article
Interfacial thermal transport between electrodes and polymer electrolytes can play a crucial role in the thermal management of solid-state lithium-ion batteries (SLIBs). Modifying the electrode surface with functional molecules can effectively increase the interfacial thermal conductance (ITC) between electrodes and polymers (e.g., electrolytes, se...
Article
Full-text available
In this study, the effects of surface roughness and pore characteristics on fatigue lives of laser powder bed fusion (LPBF) Ti–6Al–4V parts were investigated. The 197 fatigue bars were printed using the same laser power but with varied scanning speeds. These actions led to variations in the geometries of microscale pores, and such variations were c...
Article
Gallium nitride (GaN) has emerged as a quintessential wide band-gap semiconductor for an array of high-power and high-frequency electronic devices. The phonon thermal resistances that arise in GaN thin films can result in detrimental performances in these applications. In this work, we report on the thermal conductivity of submicrometer and microme...
Preprint
Full-text available
Plasma-enhanced chemical vapor deposition (PECVD) provides a low-temperature, highly-efficient, and catalyst-free route to fabricate graphene materials by virtue of the unique properties of plasma. In this paper, we conduct reactive molecular dynamics simulations to theoretically study the detailed growth process of graphene by PECVD at the atomic...
Article
Polymers of intrinsic microporosity (PIMs) have shown promise in pushing the limits of gas separation membranes, recently redefining upper bounds for a variety of gas pair separations. However, many of these membranes still suffer from reductions in permeability over time, removing the primary advantage of this class of polymer. In this work, a ser...
Preprint
Full-text available
Finding amorphous polymers with higher thermal conductivity is important, as they are ubiquitous in heat transfer applications. With recent progress in material informatics, machine learning approaches have been increasingly adopted for finding or designing materials with desired properties. However, relatively limited effort has been put into find...
Preprint
In this study, the effects of surface roughness and pore characteristics on fatigue lives of laser powder bed fusion (LPBF) Ti-6Al-4V parts were investigated. The 197 fatigue bars were printed using the same laser power but with varied scanning speeds. These actions led to variations in the geometries of microscale pores, and such variations were c...
Preprint
Full-text available
The field of plasmonic nanobubbles, referring to bubbles generated around nanoparticles due to plasmonic heating, is growing rapidly in recent years. Theoretical, simulation and experimental studies have been reported to reveal the fundamental physics related to this nanoscale multi-physics phenomenon. Using plasmonic nanobubbles for applications i...
Preprint
Full-text available
The traditional picture of heat transfer in solids by atomic vibrations, also known as phonons, involves phonons scattering with each other like gas particles and is commonly referred to as the phonon gas model (PGM). This physical picture accounts for interactions among propagating (i.e., plane wave modulated) vibrational modes in an ideal crystal...
Preprint
Full-text available
Interfacial thermal transport between electrodes and polymer electrolytes can play a crucial role in the thermal management of solid-state lithium-ion batteries (SLIBs). Modifying the electrode surface with functional molecules can effectively increase the interfacial thermal conductance (ITC) between electrodes and polymers (e.g., electrolytes, se...
Article
Full-text available
Titanium nitride (TiN) metadevices as perfect absorbers are studied using finite-difference time-domain (FDTD) simulations. In this paper, we demonstrate a metastructure including a top silica (SiO2) layer, two layers of TiN nano-ribbon arrays, a SiO2 dielectric layer, and a TiN film to realize efficient solar energy harvesting. We theoretically op...
Preprint
Interfaces impede heat flow in micro/nanostructured systems. Conventional theories for interfacial thermal transport were derived based on bulk phonon properties of the materials making up the interface without explicitly considering the atomistic interfacial details, which are found critical to correctly describing thermal boundary conductance (TB...
Article
Full-text available
High thermal conductivity materials show promise for thermal mitigation and heat removal in devices. However, shrinking the length scales of these materials often leads to significant reductions in thermal conductivities, thus invalidating their applicability to functional devices. In this work, we report on high in-plane thermal conductivities of...
Article
Full-text available
We show that the Brownian motion of a nanoparticle (NP) can reach a ballistic limit when intensely heated to form supercavitation. As the NP temperature increases, its Brownian motion displays a sharp transition from normal to ballistic diffusion upon the formation of a vapor bubble to encapsulate the NP. Intense heating allows the NP to instantane...
Article
Manipulating small objects with the optical force has benefitted various fields ranging from nano/micro-patterning techniques to bio-applications. In this paper, we theoretically study the modulation of the local optical force on a Rayleigh or Mie dielectric sphere at a given location, when the superposition of the zeroth-order Bessel beam as an in...
Article
In this article, we review thermal transport in polymers with different morphologies from aligned fibers to bulk amorphous states. We survey early and recent efforts in engineering polymers with high thermal conductivity by fabricating polymers with large-scale molecular alignments. The experimentally realized extremely high thermal conductivity of...
Preprint
Boltzmann transport equation (BTE) is an ideal tool to describe the multiscale phonon transport phenomena, which are critical to applications like microelectronics cooling. Numerically solving phonon BTE is extremely computationally challenging due to the high dimensionality of such problems, especially when mode-resolved properties are considered....
Article
Full-text available
A variety of quantum degrees of freedom, e.g., spins, valleys, and localized emitters, in atomically thin van der Waals materials have been proposed for quantum information applications, and they inevitably couple to phonons. Here, we directly measure the intrinsic optical phonon decoherence in monolayer and bulk MoS2 by observing the temporal evol...
Article
Superconducting metallic transition-metal nitrides, especially from the family of NbNx, are promising in various applications. Due to the fact that the lattice constants and the crystal structures are similar to those of GaN, GaN/NbN heterostructures have been grown to combine the benefits of superconductors and semiconductors, where the thermal tr...
Article
Full-text available
Seawater desalination plays a critical role in addressing the global water shortage challenge. Directional Solvent Extraction (DSE) is an emerging non-membrane desalination technology that features the ability to utilize very low temperature waste heat (as low as 40 °C). This is enabled by the subtly balanced solubility properties of directional so...
Article
Full-text available
The transport of fluid and ions in nano/molecular confinements is the governing physics of a myriad of embodiments in nature and technology including human physiology, plants, energy modules, water collection and treatment systems, chemical processes, materials synthesis, and medicine. At nano/molecular scales, the confinement dimension approaches...
Preprint
Photothermal surface bubbles play important roles in a wide range of applications like catalysis, microfluidics and biosensing, but their formation on a transparent substrate immersed in a plasmonic nanoparticle (NP) suspension has an unknown origin. Here, we show that NPs deposited on the substrate by dispersive optical forces are responsible for...
Article
β-Ga2O3 is a wide-bandgap semiconductor of significant technological importance for electronics, but its low thermal conductivity is an impeding factor for its applications. In this work, an interatomic potential is developed for β-Ga2O3 based on a deep neural network model to predict the thermal conductivity and phonon transport properties. Our po...
Article
Open source data in large scale are the cornerstones for data-driven research, but they are not readily available for polymers. In this work, we build a benchmark database, called PI1M (referring to ~1 million polymers for polymer informatics), to provide data resources that can be used for machine learning research in polymer informatics. A genera...
Preprint
In this article, we review thermal transport in polymers with different morphologies from aligned fibers to bulk amorphous states. We survey early and recent efforts in engineering polymers with high thermal conductivity by fabricating polymers with large-scale molecular alignments. The experimentally realized extremely high thermal conductivity of...
Article
Effective separation and transfer of photogenerated charge carriers are common issues in solar energy conversion. Strong localized electric fields near functional nanostructures reduce charge recombination and boost energy efficiency and photocatalytic activity. However, common metal-based photocatalytic systems on conducting supports under-utilize...
Article
Full-text available
Thermal rectification is an exotic thermal transport phenomenon which allows heat to transfer in one direction but block the other. We demonstrate an unusual dual-mode solid-state thermal rectification effect using a heterogeneous “irradiated-pristine” polyethylene nanofiber junction as a nanoscale thermal diode, in which heat flow can be rectified...
Article
Solar desalination that exploits interfacial evaporation represents a promising solution to global water scarcity. Real-world feedstocks (e.g., natural seawater and contaminated water) include oil contamination issues, raising a compelling need for desalination systems that offer anti-oil-fouling capability; however, it is still challenging to prep...
Article
Full-text available
A unified fundamental understanding of interfacial thermal transport is missing due to the complicated nature of interfaces. Because of the difficulty to grow high-quality interfaces and lack of materials characterization, the experimentally measured thermal boundary conductance (TBC) in the literature are usually not the same as the ideally modell...
Article
Full-text available
Capillary driven transport of liquids in nanoscopic channels is an omnipresent phenomenon in nature and technology including fluid flow in human body and plants, drug delivery, nanofluidics devices, and energy/water systems. However, the kinetics of this mass transport mechanism remains in question as the well-known Lucas-Washburn (LW) model predic...
Article
Aluminum nitride (AlN) has garnered much attention due to its intrinsically high thermal conductivity. However, engineering thin films of AlN with these high thermal conductivities can be challenging due to vacancies and defects that can form during the synthesis. In this work, we report on the cross-plane thermal conductivity of ultra-high-purity...
Article
Functionalized nanoparticles (NPs) are the foundation of diverse applications. Especially, in many biosensing applications, concentrating suspended NPs onto a surface without deteriorating their biofunction is usually an inevitable step to improve detection limit, which remains to be a great challenge. In this work, biocompatible deposition of func...
Article
Full-text available
Directed high-speed motion of nanoscale objects in fluids can have a wide range of applications like molecular machinery, nano robotics, and material assembly. Here, we report ballistic plasmonic Au nanoparticle (NP) swimmers with unprecedented speeds (~336,000 μm s−1) realized by not only optical pushing but also pulling forces from a single Gauss...
Article
Full-text available
Understanding the growth dynamics of the microbubbles produced by plasmonic heating can benefit a wide range of applications like microfluidics, catalysis, micro-patterning and photo-thermal energy conversion. Usually, surface plasmonic bubbles are generated on plasmonic structures pre-deposited on the surface subject to laser heating. In this work...
Chapter
In this chapter, an overview of the current research progress on the thermal properties of beta-gallium oxide (β-Ga2O3) is provided. Thermal properties of β-Ga2O3 are of great significance to the device reliability and performance in its potential applications. Previous research through both computational and experimental studies on β-Ga2O3 using v...
Article
Wurtzite AlN is an ultrawide bandgap semiconductor that has been developed for applications including power electronics and optoelectronics. Thermal management of these applications is the key for stable device performance and allowing for long lifetimes. However, the intrinsic high thermal conductivity of bulk AlN predicted by theoretical calculat...
Article
Molecular dynamics (MD) simulations have been extensively used to predict thermal properties, but simulating different phases with similar precision using a unified force field is often difficult because of the lack of accurate and transferrable interatomistic potential fields. As a result, this issue has become a major barrier to predicting the ph...
Preprint
p>Functionalized nanoparticles (NPs) are the foundation of diverse applications, such as photonics, composites, energy conversion, and especially biosensors. In many biosensing applications, concentrating the higher density of NPs in the smaller spot without deteriorating biofunctions is usually an inevitable step to improve the detection limit, wh...
Cover Page
Full-text available
This review surveys material development, thermal engineering, and notable innovations driving the advancement of solar-thermal water evaporation under low solar concentration, which may enable niche applications like solar water desalination and sanitization.
Article
Polyelectrolytes are important to many applications, such as electronics and batteries. In this work, we study the thermal conductivity of polyelectrolytes with different counterions using molecular dynamics (MD) simulations. Both anionic and cationic polyelectrolytes, including poly(acrylic acid) and poly(allylamine hydrogen halide), are investiga...
Preprint
div> Polyelectrolytes are important to many applications, such as electronics and batteries. In this work, we study the thermal conductivity of polyelectrolytes with different counterions using molecular dynamics (MD) simulations. Both anionic and cationic polyelectrolytes, including poly(acrylic acid) and poly(allylamine hydrogen halide), are in...
Article
Full-text available
Solar-thermal water evaporation (SWE) has received much interest in recent years due to a few seminal works on materials innovation and thermal management. With many studies proposing applications like water desalination and sanitization, SWE becomes attractive as it can use renewable energy to potentially address pressing water-energy nexus challe...