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The purpose of this paper is to answer this question by discussing the practicality of implementing microreactor technology towards large-scale renewable energy generation, as well as provide an incentive for future researchers to utilize microreactors as a useful alternative tool for green energy production. However, can microreactors present a viable solution for the generation of renewable energy to tackle the on-going global energy crisis?

In this paper, the practicality of implementing microreactor technology toward large-scale renewable energy generation is discussed. Specific areas of interest that elucidate considerable returns of microreactors toward renewable energy production are biofuel synthesis, hydrogen conversion and solar energy harvesting.

It is believed that sustained research on microreactors can significantly accelerate the development of new energy production methods through renewable sources, which will undoubtedly aid in the quest for a greener future.

This work aims to provide a sound judgement on the importance of research on renewable energy production and alternative energy management methods through microreactor technology, and why future studies on this topic should be highly encouraged. The relevance of this opinion paper lies in the idea that microreactors are an innovative concept currently used in engineering to significantly accelerate chemical reactions on microscale volumes; with the feasibility of high throughput to convert energy at larger scales with much greater efficiency than existing energy production methods.

The purpose of this paper is to focus on the technology and performance of the miniature microfluidic module for urea determination. The presented module was made using low-temperature co-fired ceramics (LTCC). It shows the possibility for the integration of the bioreceptor layers with structures that have been fabricated using modern microelectronic technology.

The presented microfluidic module was fabricated using LTCC technology. The possibility for the fabrication of an enzymatic microreactor in a multilayer ceramic substrate, made of CeramTec glass ceramic (GC) material systems with an integrated thick-film heater, is studied. Different configurations of the LTCC/heater materials (gold, silvers and palladium-silver) are taken into account. The performance of the LTCC-based microfluidic module with the integrated heater and immobilized enzyme was examined experimentally.

A compatible material for the heater embedded in the CeramTec GC-based structures was found. The preliminary measurements made for the test solution containing various concentrations of urea have shown stability (for seven days of operation) and a relatively high signal-to-noise ratio (above 3 pH units) for the microreactor’s output signal.

The presented research is a preliminary work which is focused on the fabrication of the LTCC-based microfluidic module, with an integrated heater and immobilized enzyme for urea determination. The device was positively tested using a model reaction of the hydrolysis of urea. However, urea concentration in real (biological) fluid should also be measured.

The development of the LTCC-based microfluidic module for urea determination provides opportunity for the construction of a lab-on-chip, or μTAS-type system, for fast medical diagnoses and the continuous monitoring of various biochemical parameters, e.g. for estimating the effectiveness of hemodialysis.

This paper shows the design, fabrication and performance of the novel microfluidic module for urea determination, made with LTCC technology.

The purpose of this paper is to present the research activity and results to research and development society on the field of ceramic microsystems.

The chemical reactor was developed as a non-conventional application of low temperature co-fired ceramic (LTCC) and thick-film technologies. In the ceramic reactor with a large-volume, buried cavity, filled with a catalyst, the reaction between water and methanol produces hydrogen and carbon dioxide (together with traces of carbon monoxide). The LTCC ceramic three-dimensional (3D) structure consists of a reaction chamber, two inlet channels, an inlet mixing channel, an inlet distributor, an outlet collector and an outlet channel. The inlet and outlet fluidic barriers for the catalyst of the reaction chamber are made with two “grid lines”.

A 3D ceramic structure made by LTCC technology was successfully designed and developed for chemical reactor – methanol decomposition.

Research activity includes the design and the capability of materials and technology (LTCC) to fabricate chemical reactor with large cavity. But further dimensions-scale-up is limited.

The technology for the fabrication of LTCC-based chemical reactor was developed and implemented in system for methanol decomposition.

The approach (large-volume cavity in ceramic structure), which has been developed, can be used for other type of reactors also.

This study aims to propose the increase of heat dissipation requirements of modern electronic equipment and the fast development of micro-scale manufacturing technologies. The heat transfer mechanism is studied in-depth, especially for its pattern of secondary flow caused by the repeated inversion of centrifugal force. Effects of η on the frictional pressure drop and average Nusselt number are studied and the performance of such microchannel heat sink with various bend amplitudes is comprehensively evaluated. These results can provide important insight into the optimal design of this novel design configuration for microelectronics cooling.

A three-dimensional model based on the finite volume approach and SIMPLEC algorithm is performed to test an innovative serpentine microchannel, which behaves differently from conventional serpentine microchannel due to the significant effect of centrifugal force inversion.

The effect of centrifugal force significantly influences the flow and thermal fields which are responsible for the enhancement in heat transfer coefficient. The number, size and intensity of vortices increase with increasing Re, and the vortices are reformed at every change of the geometry in a periodic fashion. The serpentine microchannel studies more effectively at larger bend amplitude. Pressure fluctuations and temperature variation are greater with increasing bend amplitude.

Several techniques have been developed to augment single-phase convective heat transfer in channels. One technique is to use a serpentine channel that enhances the heat transfer due to flow mixing and periodic interruption of thermal boundary layers. This technique has been applied to micro-heat exchangers, thermal regenerators and mini/microreactors.

The optimal design of this novel design configuration for microelectronics cooling can be attained. It will become an effective cooling technology for solving the increasing of heat dissipation requirements of modern electronic equipment.

The flow and heat transfer characteristics are first presented for the circular serpentine microchannel made up of alternate U-bends without interposed straight segments. The present study first examines the effect of such centrifugal force inversion on velocity contour, pressure distribution and temperature distribution. The patterns of secondary flow along the flow passage caused by the repeated inversion of centrifugal force are further studied in depth. The effect of bend amplitude on the flow and heat transfer is explored and the performance of such microchannel heat sink has been comprehensively evaluated.

Conventional shaping processes for ceramics are mostly based on a powder‐technological molding process using a negative mold and subsequent thermal compaction. Especially for prototypes and small lot series of microcomponents the outlay for molds are the major costing factor. Consequently the use of rapid prototyping (RP) processes can decisively reduce the costs and time in product development of ceramic microcomponents. In spite of the fact, that a large number of freeform fabrication techniques for different materials were developed in recent years, most generative techniques of ceramics still have different drawbacks for the fabrication of prototypes and often exhibit limited resolution compared to those of polymers. The combination of RP techniques such as micro stereolithography and ceramic injection molding in a RP process chain can fill in the gap between the limited applicability of solid freeform fabrication of ceramics and the restricted material properties of polymers.

Fully developed Casson fluid flow through vertical microchannel is deliberated in the presence of thermal radiation. The two predominant features of micro scale phenomenon such as velocity slip and temperature jump are considered. The paper aims to discuss this issue.

The governing equations of the physical phenomenon are solved using Runge–Kutta–Fehlberg fourth fifth order method.

The outcome of the present work is discussed through graphs. This computation shows that entropy generation rate decreases with enhancing wall ambient temperature difference ratio and fluid wall interaction parameter. Also, it is found that Bejan number is fully retarded with rise in fluid wall interaction parameter. Enhancement in heat transfer or Nusselt number is achieved by increasing the wall ambient temperature ratio and fluid wall interaction parameter.

Casson liquid flow through microchannel is analyzed by considering temperature jump and velocity slip. This computation shows that entropy generation rate decreases with enhancing wall ambient temperature difference ratio.

Aiming at finding the velocity distribution profile and other flow characteristic parameters such as the Poiseuille (Po) number, this study aims to focus on the three-dimensional forced convective flow inside rectangular ducts filled with porous media commonly used in air-based solar thermal collectors to enhance the thermal performance. The most general model for the fluid flow (i.e. the non-linear Darcy–Brinkman–Forchheimer partial differential equation subjected to slip and no-slip boundary conditions) is considered.

The general governing equations are solved analytically based on the perturbation technique and the results are validated against numerical simulation study based on a finite-difference solution over a non-uniform but structured grid.

The analytical velocity distribution profile based on exponential functions for the above-mentioned general case is obtained, and accordingly, expressions for the Po are introduced. It is found that the velocity distribution tends to be uniform by increasing the aspect ratio of the duct. Moreover, a criterion for considering/neglecting the nonlinear drag term in the momentum equation (i.e. the Forchheimer term) is proposed. According to the sensitivity analysis, results show that the nonlinear drag term effects on the Nusselt number are important only in porous media with high Darcy numbers.

A general analytic solution for three-dimensional forced convection flows through rectangular ducts filled with porous media for the general model of Darcy–Brinkman–Forchheimer and the general boundary condition including both no-slip and slip-flow regimes is obtained. An analytic expression to calculate Po number is obtained which can be practical for engineering estimations and a basis for validation of numerical simulations. A criterion for considering/neglecting the nonlinear drag term in the momentum equation is also introduced.

This paper aims presents topology optimization of microfluidic channels with reverse flow.

A circular chamber with an inlet and an outlet are chosen as an initial design domain. The energy dissipation is chosen as an objective function. The incompressible Navier–Stokes equation is applied for simulating the fluidic motion in channels. An artificial friction force which is proportional to the flow velocity is substituted into the Navier–Stokes equation for controlling the design variable.

The effect of a bifurcation angle between the inlet and the outlet on a topological structure is analyzed. The flow velocity, pressure and design variable for every bifurcation angle are obtained.

This work is instructive to the design of a microfluidic system.

This study aims to outline the current challenges in ultrasonic additive manufacturing (AM). AM has revolutionized manufacturing and offers possible solutions when conventional techniques reach technological boundaries. Ultrasonic additive manufacturing (UAM) uses mechanical vibrations to join similar or dissimilar metals in three-dimensional assemblies. This hybrid fabrication method got attention due to minimum scrap and near-net-shape products.

This paper reviews significant UAM areas in process parameters such as pressure force, amplitude, weld speed and temperature. These process parameters used in different studies by researchers are compared and presented in tabular form. UAM process improvements and understanding of microstructures have been reported. This review paper also enlightens current challenges in the UAM process, process improvement methods such as heat treatment methods, foil-to-foil overlap and sonotrode surface roughness to increase the bond quality of welded parts.

Results showed that UAM could solve various problems and produce net shape products. It is concluded that process parameters such as pressure, weld speed, amplitude and temperature greatly influence weld quality by UAM. Post-weld heat treatment methods have been recommended to optimize the mechanical strength of ultrasonically welded joints process parameters. It has been found that the tension force is vital for the deformation of the pre-machined structures and for the elongation of the foil during UAM bonding. It is recommended to critically investigate the mechanical properties of welded parts with standard test procedures.

This study compiles relevant research and findings in UAM. The recent progress in UAM is presented in terms of material type, process parameters and process improvement, along with key findings of the particular investigation. The original contribution of this paper is to identify the research gaps in the process parameters of ultrasonic consolidation.

This paper aims to present a research on utilization of an irreversible bonding between non-transparent low temperature co-fired ceramics (LTCC) and transparent poly(dimethylsiloxane) (PDMS). The research presented in this paper is focused on the technology and performance of the miniature microfluidic module for fluorescence measurement.

The chemical combination of both materials is achieved through surface modification using argon-oxygen dielectric barrier discharge (DBD) plasma. According to the performed spectroscopic analyses (X-ray photoelectron spectroscopy, XPS; attenuated total reflection-Fourier infrared spectroscopy, ATR-FTIR) and contact angle measurements, the LTCC and PDMS surfaces are oxidized during the process. The presented microfluidic module was fabricated using LTCC technology. The possibility for the fabrication of LTCC-PDMS microfluidic fluorescent sensor is studied. The performance of the sensor was examined experimentally.

As a result of DBD plasma oxidation, the LTCC and PDMS surfaces change in character from hydrophobic to hydrophilic and were permanently bonded. The presented LTCC-PDMS bonding technique was used to fabricate a microfluidic fluorescent sensor. The preliminary measurements of the sensor have proven that it is possible to observe the fluorescence of a liquid sample from a very small volume.

The presented research is a preliminary work which is focused on the fabrication of the LTCC-PDMS fluorescent sensor. The microfluidic device was positively tested only for ethanolic fluorescein solutions. Therefore, fluorescence measurements should be performed for biological specimen (e.g. DNA).

The LTCC-PDMS bonding technology combines the advantages of both materials. One the one hand, transparent PDMS with precise, transparent three-dimensional structures can be fabricated using hot embossing, soft lithography or laser ablation. On the other hand, rigid LTCC substrate consisting of microfluidic structures, electric interconnections, heaters and optoelectronic components can be fabricated. The development of the LTCC-PDMS microfluidic modules provides opportunity for the construction of a lab-on-chip, or micro-total analysis systems-type system, for analytical chemistry and fast medical diagnoses.

This paper shows utilization of the PDMS-LTCC bonding technology for microfluidics. Moreover, the design, fabrication and performance of the PDMS-LTCC fluorescent sensor are presented.