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The purpose of this paper is to design a microgripper that can achieve nondestructive gripping of a miniaturized ultra-thin-walled cylindrical part.

The microgripper is mainly made of an inflatable silica gel gasbag, which can minimize the damage to the part in the gripping process. This paper introduces the design principle of a flexible air-filled microgripper, which is applied in an in-house microassembly system with coaxial alignment function. Its parameters and performance specifications have been obtained by simulation, experiment demarcating. The results show that the microgripper is able to grasp an ultra-thin-walled part non-destructively.

For the microgripper, finite element simulations and experiments were carried out, and both results indicate that the microgripper can achieve nondestructive gripping of a miniaturized ultra-thin-walled cylindrical part, with good stability, great grasping force and high repeat positioning accuracy.

Gripping the ultra-thin-walled part may lead to deformation and destruction easily. It has been a big bottleneck hindering successful assembly. This article introduces a novel microgripper using an inflatable sac. The work is interesting from an industrial point of view for a specific category of assembly applications. It provides a theoretical guidance and technical support to design a microgripper for a miniaturized ultra-thin-walled part of different sizes.

The purpose of this paper is to investigate the performance of an ultra-thin film lubricated conjunction through the elastohydrodynamic lubrication of point contacts for various ridge shapes and sizes located within the contact zone including flat-top, triangle and cosine wave profiles, considering the influence of surface forces of solvation and Van der Waals’ in addition to the hydrodynamic effect to predict an optimum geometric characteristics for surface texture for lubricated conjunctions.

Surface features are simulated in a variety of sizes and shapes including flat-top, triangle and cosine wave profiles. While estimating the elastic deformation of the contacting surfaces, surface forces of solvation and Van der Waals’ are taken into account. The Reynolds equation is solved using the Newton–Raphson method to get the pressure profile and film thickness including the elastic deformation, and surface feature.

The geometrical characteristics of the ridge, its placement in relation to the contact zone and its height all have a significant impact on the performance of ultra-thin film lubricated conjunction. When the triangular-shaped ridge is present in contact, it forecasts even sharper peaks in film thickness and pressure. More friction, wear and eventually contact fatigue are brought on by this more acute pressure and film thickness peaks. The flat-top ridge shape shows a better performance for lubricated conjunction where, the minimum film thickness value is comparable to that obtained for the case of a smooth contact surface. This behavior is attributed to the effect of intermolecular force of solvation. An increase in the size of the ridge results in a step increase in the film thickness for different ridge shapes, particularly for the flat-topped ridge pattern.

Evaluation of the performance of elastohydrodynamic lubricated ultra-thin film conjunction related to film thickness and pressure profile for various ridge surface features of different amplitudes, shapes and sizes located through the contact zone considering the influence of surface forces of solvation and Van der Waals’ in addition to the hydrodynamic effect.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2023-0062/

The purpose of this manuscript is to present a novel, compact and ultra-thin “3”-shaped monopole antenna for wireless operations in the laptop computer. The thickness of the antenna is only 0.2 mm and is designed using only a pure copper strip of size 17.5 × 6 mm².

The simple structure of the proposed antenna consists of two monopole radiating strips, namely, AC and CD and an open-ended rectangular tuning stub BE of length 9mm.

This structure inspires two resonating modes at 3.45 and 5.5 GHz and achieves the measured impedance band width as 20% (3.21-3.91) GHz in lower band (F_l) and 15% (5.05-5.85) GHz in the upper band (F_u) for voltage standing wave ratio < 2. These two bands cover 5GHz wireless local area network (WLAN) and 3.3-3.6GHz (sub 6GHz) 5G bands. The measured radiation performance including, nearly omnidirectional radiation patterns, a stable gain of around 5 dBi and excellent efficiency around 90% in both operating bands have been achieved. Furthermore, a simplified equivalent circuit model has been derived and its simulation is performed. The simulated and measured results are in good agreement, which demonstrates the applicability of the antenna structure for WiMAX/WLAN operations in the prominent ultra-thin laptop computers.

The proposed antenna is designed without using any reactive elements, vias or matching circuits for excitation of WLAN and 5G bands in the laptop computers. The design also does not require any additional ground for mounting the antenna. The proposed antenna has a very low profile, is ultra-thin, cost-effective, easy to manufacture and can be easily embedded inside next generation laptop computers.

The ultra-thin white topping (UTW) is a cement concrete overlay of the thickness of 50–100 mm on bituminous concrete pavements with surface failures. This is a long-lasting solution without having short-term failures. This paper aims to design an ultra-thin cement concrete overlay using a developed critical stress model with sustainable concrete materials for low-volume roads.

In this research paper, a parametric study was conducted using the ultra-thin concrete overlay finite element model developed with ANSYS software, considering the significant parameters affecting the performance and development. The non-linear regression equation was formed using a damped least-squares method to predict critical stress due to the corner load of 51 kN.

The parametric study results indicate that with a greater elastic modulus of bituminous concrete, granular layer along with 100 mm thickness of concrete layer reduces the critical corner stress, interface shear stress in a significant way responsible for debonding of concrete overlay, elastic strains in the pavement further the concrete overlay can bear infinite load repetitions. From validation, it is understood that the non-linear regression equation developed is acceptable with similar research work done.

From the semi-scale experimental study, it is observed that the quaternary blended sustainable concrete overlay having a high modulus of rupture of 6.34 MPa is competent with conventional cement concrete overlay in terms of failure load. So, concrete overlay with sustainable materials of 100 mm thickness and higher elastic modulus of the layers can perform in a sustainable way meeting the environmental and long-term performance requirements.

The purpose of this study is to investigate the behavior of ultra-thin film formation at the start-up of motion for different acceleration rates and final entrainment speed, including the effect of intermolecular forces; solvation and Van der Waals’ in addition to hydrodynamic action for the elastohydrodynamic lubrication of point contact problems.

The equation of motion of the ball is considered to account for the applied force on the ball during the start-up of motion. The Newton–Raphson with Gauss–Seidel iterative method is used to solve the Reynolds, film thickness and load balance equations simultaneously. In addition to hydrodynamic effects, solvation and Van der Waals’ forces are taken into account in the calculation of bearing capacity.

The simulation results showed that the effects of acceleration rate are important for ultra-thin film formation at the start-up of motion. Increasing the rate of acceleration results in a higher value of central film thickness during the start-up of motion than the corresponding steady-state film thickness value reached at the final entrainment speed. The effects of intermolecular forces are important to prevent metal-to-metal contact during the inactive period of motion, where a constant value of film thickness is achieved regardless of the value of the acceleration rate or final entrainment speed.

The behavior of ultra-thin film formation at start-up of motion, including the effect of intermolecular forces; solvation and Van-der-Waals’ along with hydrodynamic action, are evaluated after different acceleration rates and final entrainment speeds.

This paper aims to explore the forces at work that negatively influence the self-image perceptions of young women, causing them to strive for an “ultra-thin” ideal.

Focus groups explore why and how perceived self-image influences young women’s body and perceptions and, consequently, health. Thematic qualitative analysis explores the realm of information and emotions involved with the thin-ideal.

Social contagion theory emerged with a significant impact caused by network influencers and the spread of information and emotions within social networks forces that sustain the need to be ultra-thin, even though there is abundant knowledge about adverse effects.

Future research should address limitations involving representativeness and generalizability.

Social marketing programs, including social media, should stress healthy eating habits while focusing on the importance of the self and de-emphasizing the “thin-ideal” image.

Results will assist in developing more informed and effective prevention programs, including social media campaigns, as preventative healthcare to reduce the risk of the spread of eating disorders and promote psychological health of at-risk young adults.

Micro ultra-thin tubes have important implications in aerospace, nuclear energy and other fields. In microassembly process, these parts are characterized by following reasons: the small size can easily lead to damage when gripping, even for low intensity and the parts are mainly affected by the instability of light source, for vision-based systems, the visual information about ultra-thin tubes is difficult to gather and the contact state is hard to monitor.

The paper presents a new method to adjust the position deviations based on contact forces during microassembly processes. Specific research is such that the assembly model was established based both on mechanic calculation and numerical simulation; the assembly task was carried out on an in-house microassembly system with coaxial alignment function (MSCA), the contact statements were controlled based on force sensor feedback signals and the model of the relationship between contact force and assembly deviations was established. Through a comparative study, the results of experiment and simulation differ by less than 11 per cent, validating the accuracy and feasibility of the method.

The model of assembly force and position deviations of micro ultra-thin tubes based on MSCA has been built. Besides, the assembly force threshold, and the assembly process parameters have been obtained.

The assembly process parameters obtained from experiments can be applied in the precision assembly and provide theoretical guidance and technical support to the precision assembly of the multi-scale parts.

Through a unique design and application of a photo‐elastic material a gripper was developed that was able to perform high precision assembly tasks with a robot on ultra thin‐walled(R/T300).

Recent progress in silicon—on—insulator (SOI) technologies has made possible the fabrication of high quality ultra—thin film structures. Preliminary research has demonstrated the advantage of fully—depleted SOI MOSFET's in term of speed and improved resistance to hot carrier degradation. The specific dual‐gate configuration of SOI transistors is schematically presented in Fig. 1(a).

This paper aims to investigate the effect of changing speed of the entraining motion on the formation of ultra-thin lubricating films under different elliptical ratios. The ellipticity parameter (K) varied from 1 (a ball-on-plate configuration) to 6 (a configuration approaching line contact). The influence of the ellipticity parameters, the dimensionless speed and the effects of surface forces on the formation of the minimum film thickness has been demonstrated. The demarcation boundary between region dominated by elastohydrodynamic lubrication (EHL) and that by the surface force action has been demonstrated for different elliptical ratios.

The numerical solution has been carried out, using the Newton–Raphson iteration technique, applied for the convergence of the hydrodynamic pressure. The film thickness and pressure distribution are obtained by simultaneous solution of the Reynolds’ equation, the elastic deformation (caused by hydrodynamic pressure, surface force of solvation and Van der Waals force) and the load balance equation. The operating conditions, load and speed of entraining motion, promote formation of ultra-thin films that are formed under the combined action of EHL, surface contact force of solvation and molecular interactions due to presence of Van der Waals force.

The paper provides insights about the transition between region dominated by EHL and that by the surface force action for changing ellipticity ratio (K) from 1 (a ball-on-plate configuration) to 6 (a configuration approaching line contact).

This paper fulfils an identified need to study the effect of changing ellipticity ratio on the formation of ultra-thin films that are formed under the combined action of EHL, surface contact force of solvation and molecular interactions due to presence of Van der Waals force.