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Engineering design is a complex activity that requires cross-domain knowledge and experience. Many engineering design methodologies have been proposed to describe engineering design and engineering design processes. In order to assist the implementation of these design methodologies, various design representations and design supporting tools are developed along with the methodologies. For example, the systematic approach proposed by Pahl and Beitz possesses the function structure as its design representation and the design repository as its design support. Creativity, as an essential element in engineering design, allows engineering designers to be capable of generating novel and useful design ideas. To assist the idea generation in engineering design, many creative tools including brainstorming and morphological analysis have been developed. Among all creativity tools, the theory of inventive problem solving (TRIZ), developed based on the analysis of thousands of patents, may be the only tool that could actually help engineering designers at the concept-solution location and actual problem solving stage. The TRIZ toolkit possesses several useful tools such as inventive principles and contradiction matrix that could help its users to avoid “trial and error” by employing systematic idea generation and problem solving methods. TRIZ functional analysis is an essential tool in modern TRIZ practice that helps engineering designers to analyse component interactions within the technical system and search for weaknesses that require improvements. The functional analysis diagram (FAD) provides a visualised interface that allows engineering designers to record and analyse the component interactions. Together with the TRIZ 76 standard solutions, functional analysis is an effective tool in assisting problem solving processes. While the TRIZ functional analysis is usually applied to improve the weaknesses of current designs, its feasibility in new product design has not yet been explored. The aim of this research is to develop a methodology that implements TRIZ functional analysis for new product design. In addition to the design methodology, a component database, Mechanism and Machine Element Taxonomy (MMET), has been developed as a part of design methodology to expand the knowledge space available during the design process. Several case studies including the design of a deformable surgical platform, a plan of an ecology sustainable village, and a performance assessment facility for a passive ventilation system are conducted in order to validate the design methodology. While the first two case studies aim to verify the application of FAD and MMET in function-based design processes, the latter two case studies aim to extend FAD’s application to the design of other types of technical systems. The application of both a function-based design improvement process and a new product design process have been extended and verified.

Reducing mechanical friction by improving lubrication in tribological contacts is still an important goal for researches around the word. The extensive use of lubricants in applications, ranging from heavy industry to micro-biology, makes the understanding of the mechanisms by which these lubricants behave an important challenge. The fact that certain boundary lubricating films form only on contacting surfaces implies that phenomena linked to wear may play a key role in this process. One of these phenomena is known as triboemission which refers to the emission of electrons, photons and other charged particles that occur when surfaces undergo wear. Despite the possibility that triboemission events may lead to the formation of protective boundary films and also may also be responsible for lubricant degradation, the mechanism behind this phenomenon is still not well understood. In this study, spatially resolved triboemission events were analysed in a sliding contact under vacuum condition. This was achieved using an in-house developed tribometer consisting of a system of electron multipliers coupled with a phosphor screen, which allowed the in situ visualization of emission events for the first time. A range of materials were assessed in order to understand the effects of mechanical and electrical properties on the triboemission behaviour. This showed unequivocally that conductive materials show negligible emission, while those with high electrical resistivity not only produce high levels of emission but also sustained after-emission, which has not been seen before. Moreover, following the application of certain image processing techniques, a strong correlation between the spatial distribution of emission events and the topography of surface wear features was revealed. This supports the theory that triboemission is a subset of fractoemission and arises due to the uneven distribution of charge on the opposing faces of wear cracks. It also raises the possibility of using triboemission to monitor wear in real time under high magnification. In addition to this, methods were developed to differentiate between negative, positive and neutral particles, showing that each of these is emitted simultaneously but with a different spatial distribution. Surface charge was also monitored simultaneously to emission detection, showing for the first time the interactions between triboemission and tribocharging – in particular, the generation of fractures causes emission events, which reverse the expected charging trend. This may explain tribocharging mechanisms. Finally, the use of this technique to monitor coating failure was investigated. Specifically, Diamond-Like-Carbon coating specimens were assessed in vacuum and atmosphere condition revealing that coating failure can be detected in real time by observing both emission and surface charge measurements. The results presented here shed light on poorly understood triboemission mechanisms, and helps to understand how the emission interacts with the surrounding environment.