Electro-capillary peeling of thin films.

Thin films are widely-used functional materials that have attracted much interest in academic and industrial applications. With thin films becoming micro/nanoscale, developing a simple and nondestructive peeling method for transferring and reusing the films remains a major challenge. Here, we develop an electro-capillary peeling strategy that achieves thin film detachment by driving liquid to percolate and spread into the bonding layer under electric fields, immensely reducing the deformation and strain of the film compared with traditional methods (reaching 86%).

Active control of electro-visco-fingering in Hele-Shaw cells using Maxwell stress.

Viscous fingering is an extensively observed phenomenon in porous media or Hele-Shaw cells. In general, this instability is particularly difficult to control for given fluids and geometries. Therefore, investigating a control method of viscous fingering is quite attractive.

The Influence of Background Ultrasonic Field on the Strength of Adhesive Zones under Dynamic Impact Loads.

The influence of background ultrasonic field on the ultimate dynamic strength of adhesive joints is studied using fracture mechanics analysis. Winkler foundation-type models are applied to describe the cohesion zone, and the incubation time fracture criterion is used. The challenging task is to study whether relatively weak ultrasound is able to decrease the threshold values of the external impact load depending on a joint model, such as an "elastic membrane" or "beam" approximation, and various boundary conditions at the ends.

Mode Localization and Eigenfrequency Curve Veerings of Two Overhanged Beams.

Overhang provides a simple but effective way of coupling (sub)structures, which has been widely adopted in the applications of optomechanics, electromechanics, mass sensing resonators, etc. Despite its simplicity, an overhanging structure demonstrates rich and complex dynamics such as mode splitting, localization and eigenfrequency veering. When an eigenfrequency veering occurs, two eigenfrequencies are very close to each other, and the error associated with the numerical discretization procedure can lead to wrong and unphysical computational results.

Spontaneous Motion and Rotation of Acid Droplets on the Surface of a Liquid Metal.

Self-propulsion of droplets is of great significance in many fields. The spontaneous horizontal motion and self-jumping of droplets have been well realized in various ways. However, there is still a lack of an effective method to enable a droplet to rotate spontaneously and steadily.

Geomaterials Evaluation: A New Application of Ashby Plots.

The development of fossil energy resources and the occurrence of geological hazards call for a quick and effective identification of geological situations. In this study, we present rapid evaluations of geological structures from the pure point of view of material properties. For the first time, Ashby plots are applied to the evaluation of geomaterials such as rocks and coals.

ACT001 modulates the NF-κB/MnSOD/ROS axis by targeting IKKβ to inhibit glioblastoma cell growth.

Glioblastomas are high-grade brain tumors with poor prognoses, and new therapeutic approaches for these tumors are critically needed. This study revealed the underlying mechanisms of a new orphan drug, ACT001, that is currently in clinical trials for the treatment of advanced glioblastoma in Australia and China. ACT001 significantly suppressed glioma cell proliferation and induced apoptosis and cell cycle arrest in vitro, as determined by Cell Counting Kit-8 assays and flow cytometry.

The Constructions and Pyrolysis of 3D Kerogen Macromolecular Models: Experiments and Simulations.

Kerogens are extracted from deep shales to study pyrolysis of deep shale samples. The 2D molecular models of kerogens are obtained by a series of physical and chemical experiments by which the macromolecular models of kerogens are constructed. Then, the reasonable 3D macromolecular models are established by molecular mechanics and global energy minimization.

The effect of sharp solid edges on the droplet wettability.

Understanding the role of pinning force in droplet dynamic wetting is of critical importance for surface science studies. Generally, the pinning force is only related to the surface tension and the change of contact angle. However, there is an obvious correlation between the pinning force and the surface geometry.

Probing Micro-Newton Forces on Solid/Liquid/Gas Interfaces Using Transmission Phase Shift.

Many of the nature and life systems are driven by capillary interactions on solid/liquid/gas interfaces. Here, we present a profilometry technique called transmission phase shift for visualizing the liquid/gas interfaces in three dimensions with high resolution. Using this approach, we probe the change in tiny forces with particle radius at a solid/liquid/gas interface.

Topography-induced symmetry transition of droplets on quasi-periodically patterned surfaces.

Quasi-periodic structures of quasicrystals yield novel effects in diverse systems. However, there is little investigation on employing quasi-periodic structures in morphology control. Here, we show the use of quasi-periodic surface structures in controlling the transition of liquid droplets.

Aluminum hydroxide colloid vaccine encapsulated in yeast shells with enhanced humoral and cellular immune responses.

Aluminum salt (Alum) is one of the most important immune adjuvants approved for use in humans, however it is not suitable for vaccination against various chronic infectious diseases and cancers for not being able to induce cell-mediated (Th1) immunity. Here, we encapsulated an Alum colloid inside β-glucan particles (GPs), which are a type of natural particles derived from the yeast glucan shells, to prepare hybrid GP-Alum (GP-Al) adjuvant particles with a very uniform size of 2-4 μm. These hybrid particles can be used to load antigen proteins through a simple mixing procedure, and can be highly specifically targeted to antigen-presenting cells (APCs) and strongly activate dendritic cells (DCs) maturation and cytokine secretion.

Dynamics of Dissolutive Wetting: A Molecular Dynamics Study.

Dissolutive wetting, i.e., dynamic wetting of a liquid droplet on dissolvable substrates, has been studied by molecular dynamics simulations.

A novel antigen delivery system induces strong humoral and CTL immune responses.

New strategies with the ability to enhance both the humoral and cellular immune responses remain a priority for the development of future therapeutic cancer vaccines. In this study, we took advantage of β-glucan particles (GPs) derived from Saccharomyces cerevisiae baker's yeast and a novel reverse micro-emulsion method to prepare an antigen-loaded GP carrier system for dendritic cell (DC) specific antigen delivery, followed by careful evaluation of the immune functions of the prepared particles in initiating both the humoral and cellular immune responses through in vitro and in vivo experiments. The prepared particles greatly promoted DC activation and cytokine production and cross presented the antigen to CD8 cells, inducing very strong OVA specific humoral and cellular immune responses.

The effect of a capillary bridge on the crack opening of a penny crack.

Young's relation is based on the equilibrium of horizontal components of surface tensions for a liquid droplet on a "rigid" substrate without addressing the substrate deformation induced by the net vertical component of surface tensions. Upon realizing the importance of wetting in controlling the integrity of flexible structures and electronics, the effect of a capillary bridge or a liquid droplet on the crack opening of a penny crack under the action of a far-field tensile stress is analyzed. Closed-form solutions are derived for both the crack opening and the stress intensity factor, which are functions of the size of the capillary bridge or the droplet, surface tension, and the contact angle.

Molecular dynamics simulations of the enhanced recovery of confined methane with carbon dioxide.

For the first time, the enhanced recovery of confined methane (CH4) with carbon dioxide (CO2) is investigated through molecular dynamics simulations. The adsorption energy and configuration of CH4 and CO2 on the carbon surface were compared, which shows that CO2 is a good candidate in displacing confined CH4. The energy barrier required for displacing CH4 by CO2 injection was found to depend on the displacement angle.

Mass and Force Sensing of an Adsorbate on a Beam Resonator Sensor.

The mass sensing superiority of a micro-/nano-mechanical resonator sensor over conventional mass spectrometry has been, or at least is being firmly established. Because the sensing mechanism of a mechanical resonator sensor is the shifts of resonant frequencies, how to link the shifts of resonant frequencies with the material properties of an analyte formulates an inverse problem. Besides the analyte/adsorbate mass, many other factors, such as position and axial force, can also cause the shifts of resonant frequencies.

Statics and dynamics of electrowetting on pillar-arrayed surfaces at the nanoscale.

The statics and dynamics of electrowetting on pillar-arrayed surfaces at the nanoscale are studied using molecular dynamics simulations. Under a gradually increased electric field, a droplet is pushed by the electromechanical force to spread, and goes through the Cassie state, the Cassie-to-Wenzel wetting transition and the Wenzel state, which can be characterized by the electrowetting number at the microscale ηm. The expansion of the liquid is direction-dependent and influenced by the surface topology.

A phase field model coupling lithium diffusion and stress evolution with crack propagation and application in lithium ion batteries.

Cracking and fracture of electrodes under diffusion during lithiation and delithiation is one of the main factors responsible for short life span of lithium based batteries employing high capacity electrodes. Coupling effects among lithium diffusion, stress evolution and crack propagation have a significant effect on dynamic processes of electrodes during cycling. In this paper, a phase field model coupling lithium diffusion and stress evolution with crack propagation is established.

Phase transitions of a water overlayer on charged graphene: from electromelting to electrofreezing.

We show by using molecular dynamics simulations that a water overlayer on charged graphene experiences first-order ice-to-liquid (electromelting), and then liquid-to-ice (electrofreezing) phase transitions with the increase of the charge value. Corresponding to the ice-liquid-ice transition, the variations of the order parameters indicate an order-disorder-order transition. The key to this novel phenomenon is the surface charge induced change of the orientations of water dipoles, which leads to the change of the water-water interactions from being attractive to repulsive at a critical charge value qc.

Kinetic behaviour of the cells touching substrate: the interfacial stiffness guides cell spreading.

To describe detailed behaviour of cell spreading under the influence of substrate stiffness, A549 cells cultured on the surfaces of polydimethylsiloxane (PDMS) and polyacrylamide (PAAm) with bulk rigidities ranging from 0.1 kPa to 40 kPa were in situ observed. The spreading behaviour of cells on PAAm presented a positive correlation between spreading speed and substrate stiffness.

IL-4 induces a suppressive IL-10-producing CD8+ T cell population via a Cdkn2a-dependent mechanism.

CD8(+) T cells play an important role in immune regulation and effective immune responses against tumor cells, viral infection, and intracellular pathogens. In this report, using tiger or 10BiT mice, we defined a population of IL-10-producing CD8(+) T cells that were induced by IL-4. These IL-10(+)CD8(+) T cells possessed a strong inhibitory effect on the CD4(+) T cell proliferation in an IL-10-dependent and cell contact-dependent fashion.

Wetting on flexible hydrophilic pillar-arrays.

Dynamic wetting on the flexible hydrophilic pillar-arrays is studied using large scale molecular dynamics simulations. For the first time, the combined effect of the surface topology, the intrinsic wettability and the elasticity of a solid on the wetting process is taken into consideration. The direction-dependent dynamics of both liquid and pillars, especially at the moving contact line (MCL), is revealed at atomic level.

Capillary wave propagation during the delamination of graphene by the precursor films in electro-elasto-capillarity.

Molecular dynamics simulations were carried out to explore the capillary wave propagation induced by the competition between one upper precursor film (PF) on the graphene and one lower PF on the substrate in electro-elasto-capillarity (EEC). During the wave propagation, the graphene was gradually delaminated from the substrate by the lower PF. The physics of the capillary wave was explored by the molecular kinetic theory.