nano pillar

The rapid progress of electronic devices has necessitated efficient heat dissipation within boiling cooling systems, underscoring the need for improvements in boiling heat transfer coefficient (HTC) and critical heat flux (CHF). While different approaches for micropillar fabrication on copper or silicon substrates have been developed and have shown significant boiling performance improvements, such enhancement approaches on aluminum surfaces are not broadly investigated, despite their industrial applicability...

Extracellular vesicles (EVs) originating from cancer cells incorporate various critical biomolecules that can aid in early cancer diagnosis. However, the rapid analysis of these micro vesicles remains challenging due to their nano-scale size and overlapping dimensions, hindering sufficient capture in terms of quantity and purity. In this study, an acoustofluidic device was developed to enhance the yield of immune-captured EVs. The channel of the device was modified with degradable gelatin nanoparticles (∼220 nm) to increase the surface roughness, and subsequently treated with CD63 antibodies...

Despite the attractive combinations of cell/surface interactions, biocompatibility, and good mechanical properties of Ti-6Al-4V, there is still a need to enhance the early stages of cell/surface integration that are associated with the implantation of biomedical devices into the human body. This paper presents a novel, easy and reproducible method of nanoscale and nanostructured hydroxyapatite (HA) coatings on Ti-6Al-4V. The resulting nanoscale coatings/nanostructures are characterized using a combination of Raman spectroscopy, scanning electron microscopy equipped with energy dispersive x-ray spectroscopy...

Hydrodynamics, efficiency, and loading capacity of two semi-packed columns with different cross sections (NANO 315 µm x 18 µm; CAP 1000 µm x 28 µm) and similar pillar diameter and pillar-pillar distance (respectively 5 µm and 2.5 µm) have been compared in high-pressure gas chromatography. A flow prediction tool has been first designed to determine pressure variations and hold-up time across the chromatographic system taking into account the rectangular geometry of the ducts into the semi-packed columns...

In this work, a water-soluble (hydrophilic) polymer was used to form a hydrophobic coating on silicon substrates (Si) in a two-step process comprising (i) the transformation of the polymer into an insoluble material and (ii) the structuring of this coating at nanometric and micrometric scales to achieve the desired hydrophobic behavior. Polyvinylpyrrolidone (PVP), a water-soluble commodity polymer, was crosslinked using benzophenone and UV irradiation to produce a water-insoluble PVP coating. The nanometric scale roughness of the coating was achieved by the addition of silica nanoparticles (NPs) in the coating...

To non-invasively monitor personal biological and environmental samples in Internet of Things (IoT)-based wearable microfluidic sensing applications, the particle size could be key to sensing, which emphasizes the need for particle size fractionation. Deterministic lateral displacement (DLD) is a microfluidic structure that has shown great potential for the size fractionation of micro- and nano-sized particles. This paper introduces a new externally balanced multi-section cascade DLD approach with a section-scaling technique aimed at expanding the dynamic range of particle size separation...

Quasi-two-dimensional perovskites have attracted widespread interest in developing low-cost high-quality small lasers. The nano cavity based on topologically protected valley edge states can be robust against special defects. Here, we report a high-quality two-dimensional perovskite topological photonic crystal laser based on the quantum valley Hall effect. By adjusting the position of the air holes relative to the pillar, radiation leakage in topological edge states is reduced to a large extent, electric field distribution becomes more uniform and the quality factor can be as high as 3...

Rechargeable aqueous zinc-ion batteries (AZIBs) have been highly desired due to their low cost, intrinsic safety, environmental friendliness, and great potential in large-scale power storage systems. However, their practical applications are impeded by unstable long-term electrochemical performances induced by microstructure degradation of the cathode material, hydrogen evolution reaction in the electrolyte, and dendritic growth on the zinc anode upon cycling. In this work, rubidium cations (Rb+ ) are introduced to synthesize an Rb+ -preintercalated NH4 V4 O10 (NVO-Rb) composite...

P2-phase layered cathodes play a pivotal role in sodium-ion batteries due to their efficient Na+ intercalation chemistry. However, limited by crystal disintegration and interfacial instability, bulk and interfacial failure plague their electrochemical performance. To address these challenges, a structural enhancement combined with surface modification is achieved through trace Y doping. Based on a synergistic combination of experimental results and density functional theory (DFT) calculations, the introduction of partial Y ions at the Na site (2d) acts as a stabilizing pillar, mitigating the electrostatic repulsions between adjacent TMO2 slabs and thereby relieving internal structural stress...

T-Nb2 O5 characterized by the pronounced intercalation pseudocapacitance effect, is regarded as a promising and alternative anode for fast-charging Li-ion batteries. However, its electrochemical kinetics are still hindered by the absence of sufficient and homogenous conductive wiring inside active microparticles. Herein, an in situ pillaring strategy of electronic nano-wires is proposed to slice T-Nb2 O5 laminated particles for the development of durable and fast-charging anodes for Li-ion batteries. A micro-level layered structure consisting of nano-carbon-inserted T-Nb2 O5 composite flakes is designed and enabled by successive ion exchange, slice exfoliation, in situ polymerization, and carbonization processes...

Improving the long-term cycling stability and energy density of all-solid-state lithium (Li)-metal batteries (ASSLMBs) at room temperature is a severe challenge because of the notorious solid-solid interfacial contact loss and sluggish ion transport. Solid electrolytes are generally studied as two-dimensional (2D) structures with planar interfaces, showing limited interfacial contact and further resulting in unstable Li/electrolyte and cathode/electrolyte interfaces. Herein, three-dimensional (3D) architecturally designed composite solid electrolytes are developed with independently controlled structural factors using 3D printing processing and post-curing treatment...

Three-dimensional (3D) packaging using through-Si-via (TSV) is a key technique for achieving high-density integration, high-speed connectivity, and for downsizing of electronic devices. This paper describes recent developments in TSV fabrication and bonding methods in advanced 3D electronic packaging. In particular, the authors have overviewed the recent progress in the fabrication of TSV, various etching and functional layers, and conductive filling of TSVs, as well as bonding materials such as low-temperature nano-modified solders, transient liquid phase (TLP) bonding, Cu pillars, composite hybrids, and bump-free bonding, as well as the role of emerging high entropy alloy (HEA) solders in 3D microelectronic packaging...

HYPOTHESIS: The solid fraction of the substrate is expected to influence the bouncing behavior of an impinging droplet, thereby affecting spreading and contact time. Hence, it should be possible to alter the velocity and pressure distribution of impacting droplet, and also affect the impact velocity for droplet penetration right upon impact. SIMULATIONS: We systematically investigate the impact dynamics of water droplets on pillared hydrophobic surfaces with different solid fractions using phase-field simulations...

Nanoscale strain control of exciton funneling is an increasingly critical tool for the scalable production of single photon emitters (SPEs) in two-dimensional materials. However, conventional far-field optical microscopies remain constrained in spatial resolution by the diffraction limit and thus can provide only a limited description of nanoscale strain localization of SPEs. Here, we quantify the effects of nanoscale heterogeneous strain on the energy and brightness of GaSe SPEs on nanopillars with correlative cathodoluminescence, photoluminescence, and atomic force microscopy, supported by density functional theory simulations...

We investigated absorption and field enhancements of shallow nanocavities on top of high-aspect-ratio dielectric pillars in the infrared range. The structure includes a high-aspect-ratio nanopillar array of high refractive index, with nano-cavities on top of the pillars, and a metal plane at the bottom. The enhancement factor of electric field intensity reaches 3180 in the nanocavities and peak absorption reaches 99 % . We also investigated the finite-size effect of the presented structure to simulate real experiments...

The unidirectional asymmetry transmission is demonstrated based on quasi-accidental bound states in the continuum by a one-dimensional chiral photonic crystal slab (CPhCs) composed of tilted silicon nano-pillars. The chirality breaks symmetries on the far field polarization and radiation Q -factor between the upward and downward radiation channels. Accordingly, the CPhCs only supports the unidirectional maximal asymmetry transmission at fixed incident and conical angles. The numerical simulation indicates that the CPhCs obtains a circular dichroism of 0...

Electron-induced fragmentation of the HFeCo3 (CO)12 precursor allows direct-write fabrication of 3D nanostructures with metallic contents of up to >95 at %. While microstructure and composition determine the physical and functional properties of focused electron beam-induced deposits, they also provide fundamental insights into the decomposition process of precursors, as elaborated in this study based on EDX and TEM. The results provide solid information suggesting that different dominant fragmentation channels are active in single-spot growth processes for pillar formation...

The long-lived electronic spin of the nitrogen-vacancy (NV) center in diamonds is a promising quantum sensor for detecting nanoscopic magnetic and electric fields in various environments. However, the poor signal-to-noise ratio (SNR) of prevalent optical spin-readout techniques presents a critical challenge in improving measurement sensitivity. Here, we address this limitation by coupling individual NVs to optimized diamond nanopillars, thereby enhancing the collection efficiency of fluorescence. Guided by near-field optical simulations, we predict improved performance for tall (≥5 μm) pillars with tapered sidewalls...

Currently, the main pillars in treating breast cancer involve tumorectomy pursued by hormonal, radio, or chemotherapies. Nonetheless, these approaches exhibit severe adverse effects and might suffer from tumor recurrence. Therefore, there is a considerable demand to fabricate an innovative controlled-release nano-delivery system to be implanted after tumor surgical removal to guard against cancer recurrence. In addition, combining platinum-based drugs with phytochemicals is a promising approach to improving the anticancer activity of the chemotherapeutics against tumor cells while minimizing their systemic effects...

Uniformity, sensitivity, reproducibility, and cost are the critical parameters of practical surface-enhanced-Raman-spectroscopy (SERS) substrates. Herein, we proposed a High-Aspect-Ratio-Nano-Pillar-Array (HARNPA) substrate deposited silver by physical vapor deposition (PVD) methods (e.g. E-beam evaporation, sputtering, and a two-stage intermittent sputtering) to fabricate high-performance SERS substrates. The substrate by the E-beam evaporation has a significant SERS effect, but the Raman background induced by the exposure of the polymer HARNPA limits the analyte choice...