Structural electronics has garnered significant attention in the past decade. However, there remains a lack of a systematic approach in designing and manufacturing sensors that leverage both mechanical and electronic properties of materials for different applications. In this paper, we introduce a method for designing piezoresistive force sensors utilizing structural electronics and 3D printing techniques. Based on the principles of piezoresistive force sensing, we defined the geometric profile of the sensor by simultaneously maximizing strain and ensuring as uniform as possible stress distribution across the geometry. CAD models of the sensors were then formulated based on the optimized profile and fabricated using conductive filaments and the material extrusion 3D printing technique. Subsequently, we evaluated the accuracy, the sensitivity, and part-to-part variations of the sensors during loading and unloading. The influence of environmental temperature and humidity on the sensor's response were also investigated and compensated. Experiment results demonstrated the feasibility of the proposed method and revealed potential application domains, as well as limitations of the sensors.

For heat-triggered shape-changing 3D prints, active and restrictive segments need to be 3D printed next to each other to obtain the desired morphing of an object. Current single-material methods rely on locally controlling the orientation of the printing lines to adjust the amount and direction of shrinkage. This approach, however, limits design freedom as it restricts the shape and fabrication of the objects. Moreover, it results in undesirable deformations in more complex and larger designs. Addressing these challenges, we introduce Foam2Form, a method that forms active and restrictive segments by programming the shape-memory properties of foaming PLA during the printing process.We propose to use the material in a non-foamed state for active segments and in a foamed state for restrictive and passive segments, which results in more stable 4D designs free from unwanted deformations. We present the first results of this low-cost 4D printing method and demonstrate its capabilities with various application examples.

We propose a new approach to obtain local property variations in 3D-printed objects using a single-nozzle 3D printer and one filament. We use foaming filaments which expand at different rates due to different temperatures. We present an approach to harness this varying expansion by including parameters of the 3D printing process in the design space. This makes the foaming programmable and allows for achieving a wide variety of properties from a single material. We show how objects with locally varying shade, translucency, gloss, and texture can be fabricated. Our approach turns single-nozzle 3D printers into more versatile systems while eliminating the challenges of multi-material 3D printing. This is in contrast to the drive towards an increasing number of printable materials and more complex 3D printers. We demonstrate the capability of our approach by 3D printing objects with embedded barcodes, QR codes, and varying tactile properties.

Mass Personalisation (MP) is becoming more significant to answer diversifying customer needs, as a result of the advancements in digital manufacturing. In contrary to the modular design in mass customisation, Design for MP (DfMP) proposes more profound changes in product and active user involvement in the design process, while maintaining mass efficiency. Traditional product development methodologies fall short in guiding MP, as it has the distinct differences with product variability and the customer involvement with specific needs. In this study, a dedicated design methodology for MP is presented, focussing on these key dimensions. The proposed methodology guides the designer through the development process of a user modifiable design and demonstrates how to facilitate the user involvement in reaching a personalised design. It proposes a flexible and adaptable seed design architecture, and an interactive customer co-creation process. The development of a seed design, construction of its design space, and management of the solution space with a design solution algorithm are elaborated. The application of the methodology was illustrated on the personalisation of knitted footwear, and 3D printed saxophone mouthpiece. The examples show the potential of the methodology to deal with coupled MP cases. A systematic approach to DfMP will allow expanding MP to more products, and acts as a foundation for the customer co-creation oriented design in the context of this emerging paradigm.

Saxophonists have different expectations from the saxophone mouthpiece, as it significantly affects the playability and the sound of the instrument. A mass personalization paradigm provides unique products to cater to their needs, using the flexibility of additive manufacturing. The lack of quantitative knowledge on mouthpiece design hinders the personalization attempts. This study aims to lay out how design parameters affect mouthpiece characteristics. Twenty-seven 3D-printed mouthpieces with varying design parameters are used in conjunction with an artificial blowing machine, to determine the acoustical relevance of the various mouthpiece designs on four selected mouthpiece features. The influence of the design parameters is evaluated statistically and via a case study with five saxophonists. The analysis shows that seven out of nine parameters tested affect the mouthpiece characteristics by relatively different amounts. A user study demonstrates that saxophonists confirm the results in 7 of 10 cases, and they prefer personalized mouthpieces in 4 of 5 cases. The results present a key contribution to the understanding of mouthpiece design. The findings provide valuable insights for new mouthpiece design and mouthpiece personalization.

Mass-personalization (MP) presents an opportunity to meet diversifying customer needs in consumer products market with a near mass-production efficiency. Traditional product development methodologies fall short to guide design for MP and a dedicated systematic methodology is essential. The proposed approach bases on a dynamic product template that automatically adapts with user input and produces a reliable output. This paper presents the workflow towards mass-personalization of saxophone mouthpieces with focus on design automation.

Mass-Customization (MC) has been considered to answer diversifying customer needs and reshape the consumer product market. However, after about two decades of trials, MC has been largely far from success in practice. One of the major reasons for this is considered to be a lack of user engagement with customized products and the customization process itself. Therefore, this draws the attention from what is provided to the customer to how it is provided. The user involvement in MC is in the form of co-creation and often done through online tools, also known as product configurators. In practice, these product configurators for MC frequently fail in sales conversion. This study investigates the experience for customers throughout the co-creation process in an attempt to shed light on different aspects of this experience and provide a better understanding of all contributing factors.