Utilisation of microsystems technology in radio frequency and microwave applications

The market trends of the rapidly growing communication systems require new product architectures and services that are only realisable by utilising technologies beyond that of planar integrated circuits. Microsystems technology (MST) is one such technology which can revolutionise radio frequency (RF) and microwave applications. This article discusses the enabling potential of the MST to meet the stringent requirements of modern communication systems. RF MST fabrication technologies and actuation mechanisms empower conventional processes by alleviating the substrate effects on passive devices and provide product designers with high quality versatile microscale components which can facilitate system integration and lead to novel architectures with enhanced robustness and reduced power consumption. An insight on the variety of components that can be fabricated using the MST is given, emphasizing their excellent electrical performance and versatility. Research issues that need to be addressed are also discussed. Finally, this article discusses the main approaches for integrating MST devices in RF and microwave applications together with the difficulties that need to be overcome in order to make such devices readily available for volume-production.peer-reviewe

Warpage issues in large area mould embedding technologies

The need for higher communications speed, heterogeneous integration and further miniaturisation have increased demand in developing new 3D integrated packaging technologies which include wafer-level moulding and chip-to-wafer interconnections . Wafer-level moulding refers to the embedding of multiple chips or heterogeneous systems on the wafer scale. This can be achieved through a relatively new technology consisting of thermal compression moulding of granular or liquid epoxy moulding compounds. Experimental measurements from compression moulding on 8” blank wafers have shown an unexpected tendency to warp into a cylindrical-shape following cooling from the moulding temperature to room temperature. Wafer warpage occurs primarily as a result of a mismatch between the coefficient of thermal expansion of the resin compound and the Si wafer. This paper will delve into possible causes of such asymmetric warpage related to mould, dimensional and material characteristics using finite element (FE) software (ANSYS Mechanical). The FE model of the resin on wafer deposition will be validated against the measurement results and will be used to deduce appropriate guidelines for low warpage wafer encapsulation.peer-reviewe

A concurrent engineering approach to develop BioMEMS employed in a deep brain stimulator integrated with a drug delivery system

This paper presents an Integrated Product Development (IPD) based model to specifically develop bio-medical micro-electro-mechanical-systems (BioMEMS). The concurrent engineering model is based on the IPD model phases, which are presented and formulated by the Integration DEFinition (IDEF) model- ling language. To evaluate the IPD model, a case study concerning the development of a BioMEMS device for a deep brain stimulation (DBS) system was investigated. By following the relevant mechanisms and controls in the model, a design concept of a wireless head-mounted DBS implant integrated with a drug delivery system (DDS) was conceived. The contribution of this paper is the IDEF model, which provides a road map to the product development team members in order to take a concurrent engineering approach to develop Bio-MEMS. The qualitative feedback received from the identified stakeholders, together with the quality of the case study employed, namely, an integrated DBS and DDS solution, indicate a degree of evidence that the model provides a sound basis in this direction.peer-reviewe

Development of an augmentative and alternative communication app for the Maltese language

Also published in Symposium Melitensia Vol. 15 (2019) p. 1-16Augmentative and Alternative Communication (AAC) embodies all methods of communication, serving to augment or function as an alternative to speech. Maltese children having complex communication needs use various AAC devices on a daily basis. Their conversation skills are mainly limited by two key factors. The fact that AAC users communicate up to 20 times slower than those who use regular speech is the first of these two limiting factors. The second one is the unavailability of an AAC app for the Maltese language. This paper presents the development of an AAC app targeted for the Maltese language, which provides an intelligent word suggestion mechanism to improve AAC rates. The app is based on a trigram language model which is able to predict the subsequent word by considering the previous two. The model was trained by means of a specifically created corpus and uses the Interpolated Kneser-Ney Smoothing technique to correctly resolve contexts which were not observed during training. The app enables users to retrain and update the language model, such that it may provide additional personalised word suggestions. The app was evaluated by a number of clinicians and educators who regularly work with AAC users. They remarked that it will be potentially helpful in aiding Maltese children during intervention sessions in view of its effective features. The underlying language model features an average perplexity of 90.47 when tested with non-similar training and test data and an average perplexity of 3.61 when evaluated for highly similar training and test data. The low perplexity values suggest that the language model employed in this app is remarkably accurate and is effectively performing as other trigram language models reported in the literature.peer-reviewe

Evaluating the impact of design affordances in preschool children's toy preferences

The role of toys in early childhood intervention is crucial for children to acquire and improve their skills. A study with preschool children has been carried out in order to establish, from a product design perspective, how toys' innate characteristics trigger toy preferences. It was found that children’s preference is presided by the play value that is perceived. By exploiting hedonic and pragmatic qualities, designers can embed persuasive qualities in toys. A framework for toy design is proposed as a model for a computer-aided support tool that helps toy designers reach their design goal.peer-reviewe

Evaluation of an affordance-based requirements generation tool for speech and language therapeutic toys

Task clarification poses various challenges to designers as they need to understand the different needs of users before translating the requirements into specifications and aptly conceiving product concepts in the subsequent design stage. This paper presents a descriptive study for the evaluation of a framework and its implementation as a computer-based prototype tool, proposed to assist designers in generating and understanding affordance-based requirements for speech and language therapeutic toys. Results show that early design support is beneficial to both experienced and novice designers.peer-reviewe

A user-centred design framework for the development of speech and language therapeutic toys

Therapy in early childhood is facilitated through toys and play. While mainstream toys are designed for children, therapeutic toys need to satisfy requirements from clinicians, caregivers, and children. The study presented in this paper investigated the challenges that 22 international toy designers encounter during the design process and whether support is required when developing products for speech and language therapy, through a mixed-method approach. Results show that considerable challenges are encountered during the early design stages. Nonetheless, the toy design process remains unsupported, while no support is available for designers to consider therapeutic needs. Based on the feedback received, eleven requirements were identified upon which a user-centred design support framework was proposed to assist toy designers during the task clarification stage, taking into account the affordances that therapeutic toys should have without inhibiting the creative process.peer-reviewe

Design considerations for therapeutic devices - an investigation of pre-schoolers preferences for an artefact's basic characteristics

Toys are children's first consumer products and while playing they acquire numerous skills, learn about their environment and socialise with other children and adults. Toys are adapted and used by clinicians as therapeutic devices because they allow them to create bonds and communicate with children. Aesthetical aspects should be considered early in the design process, especially since pre-schoolers’ views are still dominated by the appearance of artefacts, also known as, the perceptual salient characteristics. The study of emotions mediates the understanding of the relationships between a product, user and the process with which consumers set up preferences over products. Decisions taken in each design stage will influence whether therapeutic devices will be enjoyed by children. An experiment was carried out to test out pre-schoolers’ preferences on individual attributes: form, dimension, material (hardness and weight) and surface (appearance and texture). This study exposed dominant characteristic preferences and the fact that some are influenced by gender and age. Employing these findings in therapeutic devices will enable clinicians to better engage the children during therapy

An affordance-based requirements approach for developing therapeutic artefacts - a case study of speech and language toys

An effort to solve real-world problems through the creation of new or improved products, such as rehabilitation or therapeutic devices, requires a human-centred design approach. Lack of domain knowledge about the use context and accessibility to key experts or end users pose significant challenges to the designer during the task clarification stage in understanding the end-user requirements. This article presents a computer-based design support tool, ACQUAINT-SALTT, based on a prescriptive computer architecture that allows the generation of affordance-based requirements (ABRs) for an emerging family of products known as speech and language therapeutic toys (SALTTs). Considering affordances, the end-user requirements can be detailed as a relationship between the product and the user within a context while keeping the problem as abstract as possible without restricting creativity. A prototype therapeutic toy, Olly Speaks, was developed and evaluated through usability studies carried out with clinicians, caregivers, and pre-schoolers to assess its therapeutic impact both within and outside the clinic.peer-reviewe