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The purpose of this paper is to present a complete analysis of leaky modes within a microstructured optical fibre (MOF). Some new numerical results illustrating the versatility and accuracy of our approach are to be given.

A method involving both finite elements and perfectly matched layer (PML) is proposed.

A rigorous definition of the leaky modes is proposed that leads to a proof of the validity of the PML approach together with a rule for the choice of the PML parameters.

The choice of parameters associated with the PML are discussed in great detail. The accuracy of the constant of propagation (and especially the imaginary part) are highlighted.

This paper aims to study thermocapillarity‐induced flow of thin liquid films covering heated horizontal walls with 2D topography.

A numerical model based on the 2D solution of heat and fluid flow within the liquid film, the gas above the film and the structured wall is developed. The full Navier‐Stokes equations are solved and coupled with the energy equation by a finite difference algorithm. The movable gas‐liquid interface is tracked by means of the volume‐of‐fluid method. The model is validated by comparison with theoretical and experimental data showing a good agreement.

It is demonstrated that convective motion within a film on a structured wall exists at any nonzero Marangoni number. The motion is caused by surface tension gradients induced by temperature differences at the gas‐liquid interface due to the spatial structure of the heated wall. These simulations predict that the maximal flow velocity is practically independent from the film thickness, and increases with increasing temperature difference between the wall and the surrounding gas. It is found that an abrupt change in wall temperature causes rupture of the liquid film. The thermocapillary convection notably enhances heat transfer in liquid films on heated structured walls.

Our solutions are restricted to the case of periodic wall structure, and the flow is enforced to be periodic with a period equal to that of the wall.

The reported results are useful for design of the heat transfer equipment.

New effects in thermocapillary convection are presented and studied using a developed numerical model.

The aim of this paper is to show the effectiveness of the finite element method (FEM) to study the properties of different kinds of photonic crystal fibers (PCFs), presenting results which highlight the FEM flexibility, exploited according to the particular PCF feature under investigation.

The FEM has been applied to a new emerging class of optical fibers, the so‐called PCFs, also known as microstructured or holey fibers.

It has been shown how to design and customize the PCF cross‐section to achieve desired values of dispersion, confinement loss, nonlinear or amplification properties. Reported examples prove the FEM ability to deal with complex geometries, arbitrary refractive index steps and distribution, and to be integrated with other approaches for a better and accurate analysis of the considered fiber.

Limitation in the FEM use can be given by the required computation effort in terms of memory occupancy and time, even if computational power of modern workstations can attenuate this aspect.

The FEM can be a very powerful tool to investigate and design actual structures to be used in several fields, as telecom, sensing, fiber lasers, spectroscopy.

The novelty of the paper is given by the exploitation of the FEM feature to design a new emerging class of optical fibers, considering all numerical aspects given by the unusual characteristics of the domain and problem under investigation.

Giving textiles electronic functions while retaining the flexibility of weaves would open up new avenues for already mature textile technology. We review recent developments in this field, focusing on the combination of electronic polymers and textile fibers to make microstructured electronic systems on fiber platforms/weaves. The combinatorial possibilities inherent to crossing fibers in weaves may be exploited for large scale construction of many devices, with appropriate addressing and signaling, in processes derived from classical textile technology. The electronic elements realized on these substrates include electrochemical and field effect transistors, photovoltaic devices, and light emitting devices. We discuss the requirements for embedding electronic systems into textile due to the geometrical flexibility of textile fibers, conductivity of wires and geometries of active devices in the form of fiber crossings.

The purpose of this paper is to present a hybrid numerical simulation approach for the calculation of potential and electric field distribution considering charge and dielectric constant.

Each numerical method has its own advantages and disadvantages. The idea is to overcome the disadvantages of the corresponding numerical method by coupling with other numerical methods. An augmented finite element method (FEM), linear FEM and boundary element method are used with an efficient coupling.

The simulation model of microstructured devices is not so simple. During the simulation various types of problems will occur. It is found that by using several numerical methods these problems can be overcome and the calculation can be performed efficiently.

The present approach can be applied in 2D cases. But, in 3D cases the calculation of augmented FEM in a spherical coordinate becomes quite elaborate.

The proposed hybrid numerical simulation approach can be applied for the simulation of the electrostatic force microscope (EFM) which is a very high‐resolution measuring tool in nanotechnology. This approach can be applied also to other micro‐electro‐mechanical systems.

Since the scanning process of the EFM is dynamic, it requires the updating of the FEM mesh in each calculation time step. In the present paper, the mesh updating is achieved by an arbitrary Lagrangian‐Eulerian (ALE) method. The proposed numerical approach can be applied for the simulation of the EFM including this remeshing algorithm ALE.

The purpose of this paper is to analyze the economics of various printing processes proposed for small‐scale electronic products such as radio frequency identification tags, smart cards, and wireless sensors, and to present a new transfer printing method.

The costs of several types of microstructuring techniques were calculated from commercial product data, along with a detailed spreadsheet simulation of inkjet printing for microelectronics. A new material for transfer printing was developed, along with suitable tooling for placing small and thin dice on flexible substrates.

The cost analysis of inkjet printing suggests that it may not be substantially less expensive than conventional silicon technology for this purpose, while achieving inferior performance. Offset printing is cheaper but further from practicality. The new transfer printing process successfully prints very small silicon dice at high speed, and appears to meet the market needs with respect to cost, product performance and flexibility in readily producing different designs.

The cost analysis depends on assumptions which are not all well known, and which change with time. The new method has not yet been run in a high‐volume production mode. Such experience will be necessary to fully confirm its value.

This analysis identifies cost factors which have not been generally appreciated in public discussions of printed electronics. The transfer printing process offers a unique way to make cost‐effective use of silicon integrated circuits which are much smaller than any that appear in products today, and may have ramifications beyond the original target of tags and sensors.

Energy losses in a timing chain drives are caused by friction in chain-rail contacts. To improve the efficiency, the Chair of Machine Elements and Transmission Technology at the University of Kaiserslautern developed various experimental and simulative analysis tools as a part of the German Research Foundation (DFG)-funded 1551 priority program and the DFG Collaborative Research Centre CRC 926. With these tools, various approaches for improving the efficiency were investigated. This paper aims to illustrate the approaches and present the results achieved within the framework of the above-mentioned priority program.

A towed cylinder head test rig is used for efficiency tests on timing chain drives. In addition to the experiments, a multi-body simulation model of the timing drive was developed and used.

It was possible to find positive approaches to reduce friction power by adapting the chain tensioning force as required. This was ensured for both the stationary operating points and the transient operating processes. An efficiency improvement of up to 10 per cent could be detected. Furthermore, a possibility was found to improve the frictional power by a targeted lubrication of the chain-rail contact. Here, the efficiency could be improved by 5-6 per cent. In addition, various structures were examined on a microscopic and macroscopic level. Neutral to negative results were achieved here.

This paper makes a contribution to improve the energy efficiency of timing chain drives. Different approaches have been investigated and evaluated.

This paper aims to provide details of recent developments in robotic tactile sensing.

Following a short introduction, this paper first provides an overview of tactile sensing effects and technologies. It then discusses recent developments in tactile sensing skins. Tactile sensing for robotic prosthetics and hands is then considered and is followed by a discussion of “tactile intelligence”. Various experimental results are included. Finally, brief concluding comments are drawn.

This shows that many advanced, sensitive and technologically varied tactile sensing devices are being developed. These devices are expected to impart robots with a range of enhanced capabilities such as improved gripping and manipulation, object recognition, the control and robotic hands and prosthetics and collision detection.

Tactile sensing has an increasingly important role to play in robotics, and this paper provides a technical insight into a number of recent developments and their applications.

The purpose of this paper was prepared a Ni-based superhydrophobic coating on the surface of copper to enhence its corrosion resistance. The superhydrophobic coating (SHPC) has proven to be an effective surface treatment in corrosion protection. In this paper, a Ni-based SHPC was prepared on the surface of copper (Cu) to enhance its corrosion resistance.

The coating was prepared through a two-step electrodeposition process. The first step involves the formation of a micro-nano structure Ni layer formed by an electrodeposition process. Subsequently, the polysiloxane layer was deposited on the Ni surface to create an SHPC. The morphology, composition, structure, wettability and corrosion resistance of the coating were characterized and discussed.

The results show that the water contact angle of the as-prepared coating reaches 155.5°±1.0°. The corrosion current density (i_corr = 3.90 × 10⁻⁹ A·cm⁻²) decreased by three orders of magnitude compared to the substrate, whereas |Z|_{f = 0.01 Hz} (2.40 × 10⁶ Ω·cm²) increased by three orders of magnitude. It indicated that the prepared coating has excellent superhydrophobicity and high corrosion resistance, which can provide better protection for the substrate.

The prepared coating provides long-lasting protection for Cu and other metals and offers valuable data for developing SHPCs.