Leslie Y Yeo

Leslie Y Yeo
RMIT University | RMIT · School of Engineering

About

338
Publications
53,174
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
9,793
Citations
Additional affiliations
January 2011 - December 2012
RMIT University
January 2006 - December 2012
Monash University (Australia)
January 2004 - December 2005
University of Notre Dame

Publications

Publications (338)
Article
Full-text available
The local delivery of therapeutic small interfering RNA or siRNA to the lungs has the potential to improve the prognosis for patients suffering debilitating lung diseases. Recent advances in materials science have been aimed at addressing delivery challenges including biodistribution, bioavailability and cell internalization, but an equally importa...
Article
Full-text available
Plasma treatment constitutes an efficient method for chemical-free disinfection. A spray-based system for dispensing plasma-activated aerosols onto surfaces would facilitate disinfection of complex and/or hidden surfaces inaccessible to direct line-of-sight (for example, UV) methods. The complexity and size of current plasma generators (for example...
Article
Osteogenic Differentiation In article number 2106823, Lizebona August Ambattu, Amy Gelmi, and Leslie Y. Yeo, expose mesenchymal stem cells to minutes of high frequency (10 MHz) mechanostimulation daily in the form of surface reflected bulk waves generated on a piezoelectric substrate, leading to their early but long‐term differentiation into osteob...
Article
Stem cell fate can be directed through the application of various external physical stimuli, enabling a controlled approach to targeted differentiation. Studies involving the use of dynamic mechanical cues driven by vibrational excitation to date have, however, been limited to low frequency (Hz to kHz) forcing over extended durations (typically con...
Article
Increasing the efficiency of aerobic greywater treatment is crucial to ensure that greywater recycling can be effectively implemented in individual and community households. In this work, we demonstrate that exposing greywater samples to low intensity high frequency (MHz-order) surface acoustic waves (SAWs) during the aerobic treatment process can...
Article
Full-text available
Light‐driven directional motion is common in nature but remains a challenge for synthetic microparticles, particularly regarding collective motion on a macroscopic scale. Successfully engineering microparticles with light‐driven collective motion could lead to breakthroughs in drug delivery, contaminant sensing, environmental remediation, and artif...
Article
We exploit the enhancement of liquid transport through a graphene-epoxy film actuated by surface acoustic waves to demonstrate effective and efficient nanoparticle filtration. Unlike previously reported findings using graphene films, the addition of silver epoxy to create a composite film allows higher excitation powers to be sustained over extende...
Article
The internalization of therapeutic molecules into cells-a critical step in enabling a suite of autologous ex vivo gene and cell therapies-is highly regulated by the lipid barrier imposed by the cell membrane. Strategies to increase the efficiency of delivering these exogenous payloads into the cell, while maintaining the integrity of both the thera...
Article
Full-text available
The current quest for two-dimensional transition metal carbides and nitrides (MXenes) has been to circumvent the slow, hazardous, and laborious multistep synthesis procedures associated with conventional chemical MAX phase exfoliation. Here, we demonstrate a one-step synthesis method with local Ti3AlC2 MAX to Ti3C2T z MXene conversion on the order...
Article
Full-text available
The generation of cavitation-free radicals through evanescent electric field and bulk-streaming was reported when micro-volume of a liquid was subjected to 10 MHz surface acoustic waves (SAW) on a piezoelectric substrate [Rezk et al., J. Phys. Chem. Lett. 2020, 11, 4655−4661; Rezk et al., Adv. Sci. 2021, 8.1, 2001983]. In the current study, we have...
Article
Full-text available
Ultrasound constitutes a powerful means for materials processing. Similarly, a new field has emerged demonstrating the possibility for harnessing sound energy sources at considerably higher frequencies (10 MHz to 1 GHz) compared to conventional ultrasound (⩽3 MHz) for synthesizing and manipulating a variety of bulk, nanoscale, and biological materi...
Article
Full-text available
Exosomes are promising disease diagnostic markers and drug delivery vehicles, although their use in practice is limited by insufficient homogeneous quantities that can be produced. We reveal that exposing cells to high frequency acoustic irradiation stimulates their generation without detriment to cell viability by exploiting their innate membrane...
Article
Full-text available
Objective: Current prevention and/or treatment options for respiratory syncytial virus (RSV) infections are limited as no vaccine is available. Prophylaxis with palivizumab is very expensive and requires multiple intramuscular injections over the RSV season. Here we present proof-of-concept data using nebulized palivizumab delivery as a promising...
Article
We reveal a unique mechanism by which pure water can be dissociated to form free radicals without requiring catalysts, electrolytes or electrode contact by means of high frequency nanometer-amplitude electromechanical surface vibrations in the form of surface acoustic waves (SAWs) generated on a piezoelectric substrate. The physical undulations ass...
Article
The presence of reactive species in plasma-activated water is known to induce oxidative stresses in bacterial species, which can result in their inactivation. By integrating a microfludic chipscale nebulizer driven by surface acoustic waves (SAWs) with a low-temperature atmospheric plasma source, we demonstrate an efficient technique for in-situ pr...
Article
Owing to their large surface area and high uptake capacity, metal-organic frameworks (MOFs) have attracted considerable attention as potential materials for gas storage, energy conversion, and electrocatalysis. Various strategies have recently been proposed to manipulate the MOF surface chemistry to facilitate exposure of the embedded metal centers...
Article
The increasing prevalence of multidrug resistant bacteria has warranted the search for new antimicrobial agents as existing antibiotics lose their potency. Among these, bacteriophage therapy, as well as the administration of specific bacteriolysis agents, i.e., lytic enzymes, have emerged as attractive alternatives. Nebulizers offer the possibility...
Article
Full-text available
Particle‐based pulmonary delivery has great potential for delivering inhalable therapeutics for local or systemic applications. The design of particles with enhanced aerodynamic properties can improve lung distribution and deposition, and hence the efficacy of encapsulated inhaled drugs. This study describes the nanoengineering and nebulization of...
Article
Conventional nebulisation has the disadvantages of low aerosol output rate and potential damage to macromolecules due to high shear (jet nebulisation) or cavitation (ultrasonic nebulisation). HYDRA (HYbriD Resonant Acoustics) technology has been shown to overcome these problems by using a hybrid combination of surface and bulk sound waves to genera...
Article
The ability to spatially organise the microenvironment of tissue scaffolds unlocks the potential of many scaffold-based tissue engineering applications. An example application is to aid the regeneration process of peripheral nerve injuries. Herein, we present a promising approach for three-dimensional (3D) micropatterning of nerve cells in tissue s...
Article
There is a pressing need for efficient biological treatment systems for the removal of organic compounds in greywater given the rapid increase in household wastewater produced as a consequence of rapid urbanisation. Moreover, proper treatment of greywater allows its reuse that can significantly reduce the demand for freshwater supplies. Herein, we...
Article
Microcentrifugation constitutes an important part of the microfluidic toolkit in a similar way that centrifugation is crucial to many macroscopic procedures, given that micromixing, sample preconcentration, particle separation, component fractionation, and cell agglomeration are essential operations in small scale processes. Yet, the dominance of c...
Article
Rayleigh surface acoustic waves (SAWs) have been demonstrated as a powerful and effective means for driving a wide range of microfluidic actuation processes. Traditionally, SAWs have been generated on piezoelectric substrates, although the cost of the material and the electrode deposition process makes them less amenable as low-cost and disposable...
Article
The ability to drive efficient micromixing on a microfluidic platform is crucial for a wide range of lab-on-a-chip applications. Here, we investigate the ability of acoustic waves generated on different geometric surfaces (concave and convex) to enhance the micromixing efficiency in droplet acoustomicrofluidic systems, and, concomitantly, to reduce...
Article
Despite considerable developments associated with two-dimensional (2D) transition metal dichalcogenides owing to their outstanding mechanical, electronic and optical properties, the synthesis of large micron-dimension single-layer sheets of these materials remains a particular challenge, especially if an alternative to the slow, expensive and compl...
Article
Full-text available
The high surface area and porosity, and limitless compound and network combinations between the metal ions and organic ligands making up metal–organic frameworks (MOFs) offer tremendous opportunities for their use in many applications. While numerous methods have been proposed for the synthesis of MOF powders, it is often difficult to obtain orient...
Article
Full-text available
Tactile haptic feedback is an important consideration in the design of advanced human--machine interfaces, particularly in an age of increasing reliance on automation and artificial intelligence. In this work, we show that the typical nanometer-order surface displacement amplitudes of piezoelectric transducers---which are too small to be detectable...
Article
Full-text available
Oscillation characteristics of micro-droplets, when in partial contact with a dry and homogeneous substrate, are investigated using a volume of fluid (VOF) numerical method. Water is used as a fluid in both numerical and experimental studies. The velocity vectors are plotted along the phase boundary line, i.e. along the droplet interface, to show h...
Article
We have sought to address an existing technology gap in laboratory liquid handling capability—in particular the dispensing of sub-microliter volumes and fairly viscous liquids—through a robust, low-cost and user-friendly acoustomicrofluidic platform that facilitates rapid, reproducible and precise nanoliter sample dispensing. The solid-state chipsc...
Article
Full-text available
Seeds, which are high in protein and essential nutrients, must go through a hydration process before consumption. The ability to rapidly increase water absorption can significantly reduce the soaking time as well as the amount of energy needed for cooking seeds. Many studies in the literature employ high-power (102 W) low-frequency (104 Hz) ultraso...
Article
Full-text available
Cell contact formation, which is the process by which cells are brought into close proximity is an important biotechnological process in cell and molecular biology. Such manipulation is achieved by various means, among which dielectrophoresis (DEP) is widely used due to its simplicity. Here, we show the advantages in the judicious choice of the DEP...
Article
The majority of infectious diseases enter the body through mucosal membranes that line the ocular, nasal, oral, vaginal and rectal surfaces. As infections can be effectively prevented by instigating a local immune response in the immunocyte-rich regions of the mucosa, an efficacious route of vaccine administration is to directly target their delive...
Article
Full-text available
Liquid phase exfoliation techniques of layered crystals establish the basis for high yield production of two dimensional (2D) flakes suspension. However, such techniques generally require long processing time. The recent demonstration of piezoelectric phenomenon in non-centrosymmetric layered transition metal dichalcogenides, such as molybdenum dis...
Article
Recent breakthroughs in gene editing have necessitated practical ex vivo methods to rapidly and efficiently re-engineer patient-harvested cells. Many physical membrane-disruption or pore-forming techniques for intracellular delivery, however, result in poor cell viability, while most carrier-mediated techniques suffer from suboptimal endosomal esca...
Article
Full-text available
Correction for ‘Continuous tuneable droplet ejection via pulsed surface acoustic wave jetting’ by Jasmine O. Castro et al. , Soft Matter , 2018, DOI: 10.1039/c7sm02534c.
Article
We demonstrate improvement in synthesis yields of transition metal dichalcogenide (TMD) quantum dots (QDs) through a continuous multicycle acoustomicrofluidic nebulisation process by exploiting the unique piezoelectricity of 2D TMDs. With each successive nebulisation–condensation cycle, the QDs are progressively thinned and become increasingly unif...
Article
We report a miniaturised platform for continuous production of single or multiple liquid droplets with diameters between 60 and 500 μm by interfacing a capillary-driven self-replenishing liquid feed with pulsed excitation of focussed surface acoustic waves (SAWs). The orifice-free operation circumvents the disadvantages of conventional jetting syst...
Article
A two-dimensional hybrid numerical method that allows full coupling of the elastic motion in a piezoelectric solid (modeled using a finite-difference time-domain technique) with the resultant compressional flow in a fluid (simulated using a lattice Boltzmann scheme) is developed to study the acoustic streaming that arises in both microchannels and...
Article
While many microfluidic devices have been developed for sensing and others for actuation, few devices can perform both tasks effectively and simultaneously on the same platform. In piezoelectric sensors and actuators, this is due to the opposing operating requirements for sensing and actuation. Sensing ideally requires narrow resonant peaks charact...
Article
While the remarkable properties of 2D crystalline materials offer tremendous opportunities for their use in optics, electronics, energy systems, biotechnology, and catalysis, their practical implementation largely depends critically on the ability to exfoliate them from a 3D stratified bulk state. This goal nevertheless remains elusive, particularl...
Article
The microarray titre plate remains a fundamental workhorse in genomic, proteomic and cellomic analyses that underpin the drug discovery process. Nevertheless, liquid handling technologies for sample dispensing, processing and transfer have not progressed significantly beyond conventional robotic micropipetting techniques, which are not only at thei...
Article
New crystal morphologies, previously undiscovered, for both organic and inorganic materials are obtained by Leslie Y. Yeo and co-workers, as discussed in article number 1602040, as a consequence of the unique intermediate evaporation rate regime to which aerosol droplets, generated from a microfluidic nebulization platform utilizing a recently disc...
Article
Full-text available
Administration of drug in the form of particles through inhalation is generally preferable in the treatment of respiratory disorders. Conventional inhalation therapy devices such as inhalers and nebulizers, nevertheless, suffer from low delivery efficiencies, wherein only a small fraction of the inhaled drug reaches the lower respiratory tract. Thi...
Article
Full-text available
The Miniaturised Lab-on-a-Disc (miniLOAD) platform, which utilises surface acoustic waves (SAWs) to drive the rotation of thin millimeter-scale discs on which microchannels can be fabricated and hence microfluidic operations can be performed, offers the possibility of miniaturising its larger counterpart, the Lab-on-a-CD, for true portability in po...
Article
A novel acoustic microfluidic nebulization platform is demonstrated, which, due to its unique ability to access intermediate evaporation rate regimes—significantly faster than that in slow solvent evaporation but considerably below that achieved in spray drying, is capable of producing novel crystal morphologies that have yet to be reported in both...
Article
We report the self-organization of universal branching patterns of oil nanodroplets under the Ouzo effect [Vitale S, Katz J (2003) Langmuir 19:4105-4110]-a phenomenon in which spontaneous droplet formation occurs upon dilution of an organic solution of oil with water. The mixing of the organic and aqueous phases is confined under a quasi-2D geometr...
Article
Toroidal microstructures of nanocolloidal assemblies promise important applications ranging from sensing, catalysis, drug delivery, and separation. In this work, we will first investigate the rich dissolution dynamics of a droplet comprising a nanoparticle suspension in a binary solution, and then show that the dissolution dynamics can be a potenti...
Article
We exploit the possibility of enhancing the molecular transport of liquids through graphene films using amplitude modulated surface acoustic waves (SAWs) to demonstrate effective and efficient nanoparticle filtration. The use of the SAW, which is an extremely efficient means for driving microfluidic transport overcomes the need for the large mechan...
Article
Acoustic wave microfluidic devices, in particular those that exploit the use of surface acoustic waves (SAWs), have been demonstrated as a powerful tool for driving microfluidic actuation and bioparticle manipulation. A limitation of these devices, however, is the requirement for the fabrication of interdigital transducer electrodes on the piezoele...
Article
We report on nanoscale pillar-based hypersonic phononic crystals in single crystal Z-cut lithium niobate. The phononic crystal is formed by a two-dimensional periodic array of nearly cylindrical nanopillars 240 nm in diameter and 225 nm in height, arranged in a triangular lattice with a 300-nm lattice constant. The nanopillars are fabricated by the...
Article
The ability to drive microcentrifugation for efficient micromixing and particle concentration and separation on a microfluidic platform is critical for a wide range of lab-on-a-chip applications. In this work, we investigate the use of amplitude modulation to enhance the efficiency of the microcentrifugal recirculation flows in surface acoustic wav...
Article
The deposition of a thin graphene film atop a chip scale piezoelectric substrate on which surface acoustic waves are excited is observed to enhance its performance for fluid transport and manipulation considerably, which can be exploited to achieve further efficiency gains in these devices. Such gains can then enable complete integration and miniat...
Article
Full-text available
We report a simple method for on-demand continuous processing of composite liquid marbles with the aid of a 3D printed slide platform, which offers the potential for engineering novel functional surfaces for the production of combination drug therapies, particle-based barcode biomarkers and smart membranes, among other applications. Unlike other at...
Article
Thread-based microfluidics offer a simple, easy to use, low-cost, disposable and biodegradable alternative to conventional microfluidic systems. While it has recently been shown that such thread networks facilitate manipulation of fluid samples including mixing, flow splitting and the formation of concentration gradients, the passive capillary tran...
Article
Intense acoustically driven microcentrifugation flows are employed to enhance the assembly of cellular spheroids in the microwell of a tissue culture well plate. This ability to interface microfluidics with commonly used tissue culture plasticware is a significant advantage as it can potentially be parallelized for high throughput operation and all...
Article
Surface acoustic wave (SAW), a nanometer amplitude electroelastic wave generated and propagated on low-loss piezoelectric substrates (such as LiNbO3), is an extremely efficient solid–fluid energy transfer mechanism. The present study explores the use of SAW nebulization as a solution for effective pulmonary peptide delivery. In vitro deposition...
Article
On page 1970, L. Y. Yeo and co-workers unravel and elucidate the existence of what they term a surface reflected bulk wave (SRBW), and show, quite counterintuitively, that it is possible to obtain an order-of-magnitude improvement in microfluidic manipulation efficiency, and, in particular, nebulization, through a unique combination of surface and...
Article
Surface phonon cavities that are homogenous in both mechanical and dielectric properties are reported. The cavities are formed by the placement of a defect of a single domain within periodic domain inversion of single crystal piezoelectric lithium niobate that exhibits surface phononic bandgap through the phonon-polariton coupling. Surface cavity r...