A Lego-Like Reconfigurable Microfluidic Stabilizer System with Tunable Fluidic RC Constants and Stabilization Ratios.

In microfluidic systems, it is important to maintain flow stability to execute various functions, such as chemical reactions, cell transportation, and liquid injection. However, traditional flow sources, often bulky and prone to unpredictable fluctuations, limit the portability and broader application of these systems. Existing fluidic stabilizers, typically designed for specific flow sources, lack reconfigurability and adaptability in terms of the stabilization ratios.

Characterization of Residual Stress in SOI Wafers by Using MEMS Cantilever Beams.

Silicon-on-insulator (SOI) wafers are crucial raw materials in the manufacturing process of microelectromechanical systems (MEMS). Residual stresses generated inside the wafers during the fabrication process can seriously affect the performance, reliability, and yield of MEMS devices. In this paper, a low-cost method based on mechanical modeling is proposed to characterize the residual stresses in SOI wafers in order to calculate the residual stress values based on the deformation of the beams.

A Capacitive MEMS Inclinometer Sensor with Wide Dynamic Range and Improved Sensitivity.

This paper proposes a novel capacitive liquid metal microelectromechanical system (MEMS) inclinometer sensor and introduces its design, fabrication, and signal measurement. The sensor was constructed using three-layer substrates. A conductive liquid droplet was rolled along an annular groove of the intermediate substrate to reflect angular displacement, and capacitors were used to detect the position of the droplet.

A Deformation of a Mercury Droplet under Acceleration in an Annular Groove.

Microelectromechanical system (MEMS) liquid sensors may be used under large acceleration conditions. It is important to understand the deformation of the liquid droplets under acceleration for the design and applications of MEMS liquid sensors, as this will affect the performance of the sensors. This paper presents an investigation into the deformation of a mercury droplet in a liquid MEMS sensor under accelerations and reports the relationship between the deformation and the accelerations.

Graphene platelet reinforced copper composites for improved tribological and thermal properties.

In this work, investigations were conducted to evaluate a type of graphene platelet-reinforced copper (GPL/Cu) composite for enhanced tribological and thermal properties. The pin-on-disc (steel) results show that the wear loss and the friction coefficient of the composites decrease by nearly 80% and 70%, respectively, in comparison with those of pure Cu. Thermal conductivity of the composites initially improves substantially by approximately 30% with a slight loading of 0.

Multiscale three-dimensional surface reconstruction and surface roughness of porcine left anterior descending coronary arteries.

The aim of this study was to investigate the multiscale surface roughness characteristics of coronary arteries, to aid in the development of novel biomaterials and bioinspired medical devices. Porcine left anterior descending coronary arteries were dissected , and specimens were chemically fixed and dehydrated for testing. Surface roughness was calculated from three-dimensional reconstructed surface images obtained by optical, scanning electron and atomic force microscopy, ranging in magnification from 10× to 5500×.

Microfabrication of Net Shape Zirconia/Alumina Nanocomposite Micro Parts.

Recently, there are growing demands in manufacturing of net shape micro parts for wide range of applications due to the increasing interest in miniaturization. In this paper, the fabrication of tetragonal phase zirconia/alumina (YSZ/Al₂O₃) nanocomposite micro-parts with high quality is presented. The fabrication process is based on soft lithography and colloidal powder dispersion.

Carbon Nanotube Array Based Binary Gabor Zone Plate Lenses.

Diffractive zone plates have a wide range of applications from focusing x-ray to extreme UV radiation. The Gabor zone plate, which suppresses the higher-order foci to a pair of conjugate foci, is an attractive alternative to the conventional Fresnel zone plate. In this work, we developed a novel type of Beynon Gabor zone plate based on perfectly absorbing carbon nanotube forest.

Graphene-Alumina Nanocomposites with Improved Mechanical Properties for Biomedical Applications.

This paper presents a study on graphene platelet (GPL)-reinforced alumina (Al2O3) ceramic composites and the relationships between the loading of GPL and both mechanical properties and in vitro biocompatibility. Al2O3 powders with different GPL contents were prepared and sintered using a gas protected pressure-less furnace. The examination of the results shows the density of the composites varying from 99.

Laser directed writing of flat lenses on buckypaper.

Laser directed patterning of carbon nanotubes-based buckypaper for producing a diffractive optical device is presented here. Using a laser ablation method the buckypaper was patterned into a binary Fresnel zone plate lens. Computational modelling was performed which revealed excellent focusing performance of the lens for both visible and THz radiations.

A comprehensive study on technologies of tyre monitoring systems and possible energy solutions.

This article presents an overview on the state of the art of Tyre Pressure Monitoring System related technologies. This includes examining the latest pressure sensing methods and comparing different types of pressure transducers, particularly their power consumption and measuring range. Having the aim of this research to investigate possible means to obtain a tyre condition monitoring system (TCMS) powered by energy harvesting, various approaches of energy harvesting techniques were evaluated to determine which approach is the most applicable for generating energy within the pneumatic tyre domain and under rolling tyre dynamic conditions.

Surface plasmon enhanced photoluminescence of ZnO nanorods by capping reduced graphene oxide sheets.

A hybrid structure of reduced graphene oxide (rGO) sheets/ZnO nanorods was prepared and its photoluminescence intensity ratio between the UV and defect emission was enhanced up to 14 times. By controlling the reduction degree of rGO on the surface of ZnO nanorods, the UV emission was tuned with the introduction of localized surface plasmons resonance of rGO sheets. The suppression of the defect emission was ascribed to the charge transfer and decreased with the distance between the rGO and ZnO nanorods.

Efficiency enhancement of a cantilever-based vibration energy harvester.

Extracting energy from ambient vibration to power wireless sensor nodes has been an attractive area of research, particularly in the automotive monitoring field. This article reports the design, analysis and testing of a vibration energy harvesting device based on a miniature asymmetric air-spaced cantilever. The developed design offers high power density, and delivers electric power that is sufficient to support most wireless sensor nodes for structural health monitoring (SHM) applications.

Investigation of techniques for the measurement of articular cartilage surface roughness.

Articular cartilage is the bearing surface of synovial joints and plays a crucial role in the tribology to enable low friction joint movement. A detailed understanding of the surface roughness of articular cartilage is important to understand how natural joints behave and the parameters required for future joint replacement materials. Bovine articular cartilage on bone samples was prepared and the surface roughness was measured using scanning electron microscopy stereoscopic imaging at magnifications in the range 500× to 2000×.

Estimation of AFM tip shape and status in linewidth and profile measurement.

An atomic force microscopy image is a dilation of the specimen surface with the probe tip. Tips wear or are damaged as they are used. And AFM tip shape and position status make AFM images distorted.

Fabrication of Nickel Nanostructure Arrays Via a Modified Nanosphere Lithography.

In this paper, we present a modified nanosphere lithographic scheme that is based on the self-assembly and electroforming techniques. The scheme was demonstrated to fabricate a nickel template of ordered nanobowl arrays together with a nickel nanostructure array-patterned glass substrate. The hemispherical nanobowls exhibit uniform sizes and smooth interior surfaces, and the shallow nanobowls with a flat bottom on the glass substrate are interconnected as a net structure with uniform thickness.

Surface properties of glass micropipettes and their effect on biological studies.

In this paper, an investigation on surface properties of glass micropipettes and their effect on biological applications is reported. Pipettes were pulled under different pulling conditions and the effect of each pulling parameter was analyzed. SEM stereoscopic technique was used to reveal the surface roughness properties of pipette tip and pipette inner wall in 3D.

Macroscopic invisibility cloaking of visible light.

Invisibility cloaks, which used to be confined to the realm of fiction, have now been turned into a scientific reality thanks to the enabling theoretical tools of transformation optics and conformal mapping. Inspired by those theoretical works, the experimental realization of electromagnetic invisibility cloaks has been reported at various electromagnetic frequencies. All the invisibility cloaks demonstrated thus far, however, have relied on nano- or micro-fabricated artificial composite materials with spatially varying electromagnetic properties, which limit the size of the cloaked region to a few wavelengths.

Synthesis of sealed sponge ZnO nanospheres through a novel NH(3)-evaporation method.

Sealed sponge ZnO nanospheres are prepared through a novel NH(3)-evaporation method. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and N(2) physisorption analysis show that the samples obtained are ZnO nanospheres with hexagonal wurtzite structure. The particle size is in the range 80-130 nm and the pores inside are estimated to be in the range 2-35 nm.