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Weld‐bonding combines the physical force‐based process of welding with the chemical force‐based process of bonding or, more properly, adhesive bonding. When done properly, the claim is that a hybrid process results which offers the best of both processes; the high joint efficiency, resistance to diverse and complex loading, and temperature tolerance of welding; the load‐spreading, stress concentration‐softening, and structural damage tolerance of adhesive bonding. And, beyond these individual process attributes, there are claims, or at least predictions, of synergistic benefits in the form of improved energy absorption and fatigue life for demanding applications. However, it is difficult to find reliable data in the open literature to support these real or potential benefits. Furthermore, complications in performing the hybrid process in practice place an even greater premium on process control than normal. This paper explores the question, “Is it all worth it?” The paper delves into the theory underlying weld‐bonding, the facts concerning the process including pluses and pitfalls, and considers where the process could or should go from here.

The purpose of this paper is to provide a review of recent progress into the development of biomimetic adhesives, particularly those that mimic the attachment mechanism of the gecko lizard's foot.

This paper first discusses the discovery of the gecko's adhesion mechanism. It then describes key “gecko glue” developments and summarises the properties of experimental adhesives that exploit this effect. It concludes with a consideration of anticipated applications.

This paper shows that, following the discovery of the gecko's adhesion mechanism in 2002, which is based on van der Waals forces, biomimetic adhesives have become the topic of a major research effort. These developments are poised to yield families of novel adhesive materials with superior properties which are likely to find uses in industries ranging from defence and nanotechnology to healthcare and sport.

The paper provides a unique insight into the latest developments in biomimetic adhesive technology.

This paper aims to provide an insight into recent innovations in adhesive technology by considering a selection of commercial developments and academic research activities.

Following an introduction, this paper first discusses a selection of commercially developed adhesives used in the healthcare, photovoltaics and aerospace industries. It then considers biomimetic adhesive research, specifically dry adhesives which mimic the principles of gecko adhesion and wet adhesives based on the chemistry which underpins mussel adhesion. Finally, brief concluding comments are drawn.

This shows that new adhesives continue to be developed to meet a growing range of industrial requirements, and a major research effort into biologically inspired adhesion mechanisms is poised to yield new families of high-performance adhesives.

This provides details of recent commercial and academic developments in adhesive technology.

Being inherently a non‐pressure fusion process, laser‐beam welding (LBW) has been shown to have difficulty compared to resistance spot welding for weld‐bonding Al alloy structures, despite the many structural and manufacturing productivity advantages. Study of laser‐beam weld‐bonding of Al‐alloy structure for automobile assembly has led to a technique that appears to have both technical feasibility and production utility. The use of LBW through a hole in a pressure‐applying probe has proven to allow the production of contamination‐free spot welds through pre‐applied pre‐cured structural adhesive. The general approach, along with some details to still be overcome, is presented for both information and solution.

Discusses the use of adhesives for structural bonding. Explores the range of adhesives available and how to make the correct application choice. Outlines the advantages and limitations of bonded joints, looking at the importance of joint design, surface preparation and application methods. Notes the need for a good quality control programme and gives examples of NDT apparatus that can be used to test the integrity of a joint. Concludes that new adhesive products are continually being developed for specific combinations of materials and application methods, enabling the designer to produce cheaper, better and environmentally friendlier products.

Discusses the use of piperylene‐styrene copolymer (PSC) for polychloroprene adhesive modification. States that PSC significantly improves modified adhesive properties ‐ bond strength, viscosity, high heat resistance, good adhesion to a variety of substrates, compatibility with other adhesive additives. Looks at the advantage of using more environmentally friendly technology for thermoplastic rubber bonding with PSC modified polychloroprene adhesives. Concludes that the new adhesive product can be used for specific combinations of materials and application methods, making it possible to produce cheaper and better products.

This paper proposes a classification scheme for the quantified analysis of micro‐grip principles. Micro‐part gripping has received quite some attention in micro‐assembly research. However, there is a lack of quantified data on the characteristics and applicability of micro‐grip principles. The micro‐grip principle is the physical principle that produces the necessary forces to get and maintain a part in a position with respect to the gripper. The classification scheme defines criteria that are essential in the evaluation and selection of a micro‐grip principle for gripping a given part. The criteria are defined on the basis of characteristics of the parts to be gripped, demands on the grip operation to be performed and characteristics of the environment in which the grip operation takes place. The classification scheme is evaluated using examples from literature.

AIRCRAFT structural engineers have long been intrigued by the possibility of eliminating the thousands of assembly operations involved in a typical airframe structure—one composed of many formed pieces joined by rivets and bolts—and of replacing these multiple operations with a double, or even a single, automatic operation employing simply temperature and pressure.

Additive manufacturing (AM) is a promising alternative to the conventional production methods (i.e., machining), providing the developers with great geometrical and topological freedom during the design and immediate prototyping customizability. However, frictional characteristics of the AM surfaces are yet to be fully explored, making the control and manufacturing of precise assembly manufactured mechanisms (i.e., robots) challenging. The purpose of this paper is to understand the tribological behavior of fused deposition modeling (FDM) manufactured surfaces and test the accuracy of existing mathematical models such as Amontons–Coulomb, Tabor–Bowden, and variations of Hertz Contact model against empirical data.

Conventional frictional models Amontons–Coulomb and Tabor–Bowden are developed for the parabolic surface topography of FDM surfaces using variations of Hertz contact models. Experiments are implemented to measure the friction between two flat FDM surfaces at different speeds, normal forces, and surface configuration, including the relative direction of printing stripes and sliding direction and the surface area. The global maximum measured force is considered as static friction, and the average of the local maxima during the stick-slip phase is assumed as kinematic friction. Spectral analysis has been used to inspect the relationship between the chaos of vertical wobbling versus sliding speed.

It is observed that the friction between the two FDM planes is linearly proportional to the normal force. However, in contrast to the viscous frictional model (i.e., Stribeck), the friction reduces asymptotically at higher speeds, which can be attributed to the transition from harmonic to normal chaotic vibrations. The phase shift is investigated through spectral analysis; dominant frequencies are presented at different pulling speeds, normal forces, and surface areas. It is hypothesized that higher speeds lead to smaller dwell-time, reducing creep and adhesive friction consequently. Furthermore, no monotonic relationship between surface area and friction force is observed.

Due to the high number of experimental parameters, the research is implemented for a limited range of surface areas, which should be expanded in future research. Furthermore, the pulling position of the jaws is different from the sliding distance of the surfaces due to the compliance involved in the contact and the pulling cable. This issue could be alleviated using a non-contact position measurement method such as LASER or image processing. Another major issue of the experiments is the planar orientation of the pulling object with respect to the sliding direction and occasional swinging in the tangential plane.

Given the results of this study, one can predict the frictional behavior of FDM manufactured surfaces at different normal forces, sliding speeds, and surface configurations. This will help to have better predictive and model-based control algorithms for fully AM manufactured mechanisms and optimization of the assembly manufactured systems. By adjusting the clearances and printing direction, one can reduce or moderate the frictional forces to minimize stick-slip or optimize energy efficiency in FDM manufactured joints. Knowing the harmonic to chaotic phase shift at higher sliding speeds, one can apply certain speed control algorithms to sustain optimal mechanical performance.

In this study, theoretical tribological models are developed for the specific topography of the FDM manufactured surfaces. Experiments have been implemented for an extensive range of boundary conditions, including normal force, sliding speed, and contact configuration. Frictional behavior between flat square FDM surfaces is studied and measured using a Zwick tensile machine. Spectral analysis, auto-correlation, and other methods have been developed to study the oscillations during the stick-slip phase, finding local maxima (kinematic friction) and dominant periodicity of the friction force versus sliding distance. Precise static and kinematic frictional coefficients are provided for different contact configurations and sliding directions.

Wafer transfer robots play a significant role in IC manufacturing industry and the end effector is an important component of the robots. The purpose of this paper is to improve transfer efficiency of a wafer transfer robot through study of its end effector, and at the same time to reduce wafer deformation.

Finite element method is adopted to analyze wafer deformation. For wafer transfer robot working in vacuum, for the first time, the authors apply the research of microfiber arrays inspired by gecko to the design of robot's end effector, and present equations between robot's transit acceleration and parameters of microfiber arrays. Based on these studies, a kind of micro‐array bump is designed and fixed to a structure optimized end effector. For wafer transfer robot working in atmospheric environment, the authors have analyzed the effects of different factors on wafer deformation. The pressure distributions in absorption area and calculation formula of maximal transfer acceleration are put forward. Finally, a new kind of end effector for atmospheric robot is designed according to these studies.

The experiments results show that transfer efficiency of wafer transfer robot has been significantly improved through application of the research in this paper. Also wafer deformation under absorption force has been controlled.

Through experiments it can be seen that the research in this paper can be used to improve robot transfer ability and decrease wafer deformation in the production environment. Also the studies of end effector lay a solid foundation for further improvement.

This is the first application of the research of gecko‐inspired microfiber arrays to vacuum wafer transfer robot. This paper also carefully analyzes effects of different factors on wafer deformation through finite element method.