Thermal gelation was studied for aqueous gelling solutions of a methylcellulose. An attempt made to elucidate the gel network structure and validity scaling laws. observed on heating, it reverted liquid state cooling. The thermoreversibility heating/cooling rate dependent process. For isothermally stabilized samples, 42.5 °C found be critical temperature differentiating weak gels from strong gels. Below °C, elasticity evolved by following law with as Ge ∼ [(T − Tc)/Tc]2.93 where is...

Aqueous solutions of a methylcellulose, ranging from 0.30 to 2.49 wt %, were studied by means micro differential scanning calorimetry (micro DSC) and rheology. The effects polymer concentration on the thermodynamic properties these examined through heating process following cooling at fixed rate 1 °C/min. Upon heating, an endothermic peak was observed about 63 °C, which independent concentration. total energy defined area found be linear function On other hand, when samples 90 broad...

Abstract Microcantilevers, one of the most common MEMS structures, have been introduced as a novel sensing paradigm nearly decade ago. Ever since, technology has emerged to find important applications in chemical, biological and physical areas. Today stands at verge providing next generation sophisticated sensors (such artificial nose, tongue) with extremely high sensitivity miniature size. The article provides an overview modes detection, theory behind transduction mechanisms, materials...

This paper presents a novel approach of mixing two laminar flowing streams in microchannels. The mixer consists pair electrodes disposed along fluidic channel. By energizing the with DC-biased (2.5 V) AC voltage (20 Vpp), an electrokinetic flow is induced profile perpendicular to that incoming liquids be mixed. As result, lines and are forced crossover very efficient stirring at short length can achieved. operated from AC-electroosmotic (ACEO) (sigma=1 mS/m, f=100 kHz) AC-electrothermal...

Microfluidic biochips hold great potential for liquid analysis in biomedical research and clinical diagnosis. However, the lack of integrated on-chip mixing, bioseparation signal transduction presents a major challenge achieving rapid, ultrasensitive bioanalysis simple microfluidic configurations. Here we report magnetic nanochain chip built upon synergistic functions nanochains as nanoscale stir bars rapid mixing capturing agents specific bioseparation. The use enables planar design...

Appropriate control of substrate surface properties prior to inkjet printing could be employed improve the quality fine resolution structures. In this paper, novel methods fabricate patterned surfaces with a combination hydrophilic and hydrophobic are investigated. The results PEDOT/PSS conductive ink on these modified presented. Selective wetting was achieved via two-step hydrophilic–hydrophobic coating 3-aminopropyl trimethoxysilane (APTMS) 3M electronic grade chemical respectively PET...

Inkjet printing has proven to be a promising and flexible process methodology for low cost drop-on-demand pattern formation in small-scale production of micro-electro-mechanical systems. To optimize the micro-patterns formed by inkjet printing, an accurate control droplet volume is essential critical. In this study, system with nozzle driven circular piezoelectric element was used explore impact different waveforms on volume. The investigation into study included unipolar, bipolar, M-shaped...

Abstract Soft lithography technology allows for the development of numerous PDMS‐based microfluidic devices manipulation particles and cells. However, integrating metallic electrodes with channel structures is challenging due to weak adhesion between metal PDMS. To overcome this issue, we develop a new device continuous sorting separation microparticles by size using AC dielectrophoresis (DEP) 3‐D conducting PDMS composites as sidewall electrodes. The are synthesized mixing silver powders...

This paper reports an investigation on the effects of laser power and processing speed depth, width surface profiles microchannels manufactured from polymethyl methacrylate (PMMA) various molecular weights. The CO2 employed has a wavelength 10.6 µm maximum 25 W. used for channel fabrication varied between 0.275 2.5 W cutting ranged 7.0 to 64 mm s−1. It is observed that depth varies linearly with increase in at particular speed. For prescribed power, decreased all grades PMMA. increased but...

We present a new approach to enhance mixing in T-type micromixers by introducing constriction the microchannel under periodic electro-osmotic flow. Two sinusoidal ac electric fields with 180 degrees phase difference and similar dc bias are applied at two inlets. The out of field induces oscillation fluid interface junction inlet channels constriction. Due introduced junction, fluids from these inlets form alternative plugs constricted channel. These radiate downstream into large channel...

A gecko's superb ability to adhere surfaces is widely credited the large attachment area of hierarchical and fibrillar structure on its feet. The combination these two features provides necessary compliance for gecko toe-pad effectively engage a high percentage spatulae at each step any kind surface topography. With use multi-tiered porous anodic alumina template capillary force assisted nanoimprinting, we have successfully fabricated gecko-inspired topography branched nanopillars stiff...

Abstract Solar irradiation is a promising resource for sustainable energy conversion and storage in many technological fields. Interfacial solar steam generator emerging as system water harvesting under natural irradiance. However, sunlight usually insufficient conventional interfacial (2D absorber) generators to achieve high efficiency (>85%). Herein, functionalized MXene‐polymeric membrane‐based heat localization structure reported an efficient desalination system. The MXene flakes are...

Abstract The cooling process is of great importance in plastic injection moulding as it has a direct impact on both productivity and product quality. Cooling optimization sophisticated task which includes not only the design channels but also selection parameters. Most existing systems focus either channel or parameter both. This paper explores an approach to optimize condition simultaneously through evolutionary algorithm. prototype system proposed this integration genetic algorithm CAE...

The effects of a salt mixture consisting salt-out (NaCl) and salt-in (NaI) on the sol-gel transition methylcellulose (MC) in aqueous solution have been studied by means micro differential scanning calorimetry rheometry. was found to combined effect from salts mixture, dependent water hydration abilities component ions ion concentration. At fixed total concentration, temperature nicely followed rule mixing: Tp = m1Tp1 + m2Tp2 where Tp, Tp1, Tp2 are gelation peak temperatures for MC solutions...

Abstract Joule heating is inevitable when an electric field applied across a conducting medium. It would impose limitations on the performance of electrokinetic microfluidic devices. This article presents 3‐D mathematical model for and its effects EOF electrophoretic transport solutes in channels. The governing equations were numerically solved using finite‐volume method. Experiments carried out to investigate associated phenomena verify numerical models. A rhodamine B‐based thermometry...

The conventional microfluidic H filter is modified with multi-insulating blocks to achieve a flow-through manipulation and separation of microparticles. device transports particles by exploiting electro-osmosis electrophoresis, manipulates utilizing dielectrophoresis (DEP). Polydimethylsiloxane (PDMS) fabricated in the main channel PDMS induce nonuniform electric field, which exerts negative DEP force on particles. use not only enhances generated, but it also increases controllability motion...

Controlled modification of surface wettability polymethyl methacrylate (PMMA) was achieved by irradiation PMMA with femtosecond laser pulses at various fluences and focus distances. Fluences from 0.40 to 2.1 J/cm2 produced a hydrophobic 52.7 (maximum investigated) hydrophilic surface. less than 0.31 had no effect on the raw PMMA. This change in caused dominantly induced chemical structure not roughness.