PhysioSkin: Rapid Fabrication of Skin-Conformal Physiological Interfaces

Advances in rapid prototyping platforms have made physiological sensing accessible to a wide audience. However, off-the-shelf electrodes commonly used for capturing biosignals are typically thick, non-conformal and do not support customization. We present PhysioSkin, a rapid, do-it-yourself prototyping method for fabricating custom multi-modal physiological sensors, using commercial materials and a commodity desktop inkjet printer. It realizes ultrathin skin-conformal patches (~1μm) and interactive textiles that capture sEMG, EDA and ECG signals. It further supports fabricating devices with custom levels of thickness and stretchability. We present detailed fabrication explorations on multiple substrate materials, functional inks and skin adhesive materials. Informed from the literature, we also provide design recommendations for each of the modalities. Evaluation results show that the sensor patches achieve a high signal-to-noise ratio. Example applications demonstrate the functionality and versatility of our approach for prototyping a next generation of physiological devices that intimately couple with the human body

TrackballWatch: Trackball and Rotary Knob as a Non-Occluding Input Method for Smartwatches in Map Navigation Scenarios

A common problem of touch-based smartwatch interaction is the occlusion of the display. Although some models provide solutions like the Apple “digital crown” or the Samsung rotatable bezel, these are limited to only one degree of freedom (DOF). Performing complex tasks like navigating on a map is still problematic as the additional input option helps to zoom, but touching the screen to pan the map is still required. In this work, we propose using a trackball as an additional input device that adds two DOFs to prevent the occlusion of the screen. We created several prototypes to find a suitable placement and evaluated them in a typical map navigation scenario. Our results show that the participants were significantly faster (15.7 %) with one of the trackball setups compared to touch input. The results also show that the idle times are significantly higher with touch input than with all trackball prototypes, presumably because users have to reorient themselves after panning with finger occlusion

Like a Second Skin: Understanding How Epidermal Devices Affect Human Tactile Perception

The emerging class of epidermal devices opens up new opportunities for skin-based sensing, computing, and interaction. Future design of these devices requires an understanding of how skin-worn devices affect the natural tactile perception. In this study, we approach this research challenge by proposing a novel classification system for epidermal devices based on flexural rigidity and by testing advanced adhesive materials, including tattoo paper and thin films of poly (dimethylsiloxane) (PDMS). We report on the results of three psychophysical experiments that investigated the effect of epidermal devices of different rigidity on passive and active tactile perception. We analyzed human tactile sensitivity thresholds, two-point discrimination thresholds, and roughness discrimination abilities on three different body locations (fingertip, hand, forearm). Generally, a correlation was found between device rigidity and tactile sensitivity thresholds as well as roughness discrimination ability. Surprisingly, thin epidermal devices based on PDMS with a hundred times the rigidity of commonly used tattoo paper resulted in comparable levels of tactile acuity. The material offers the benefit of increased robustness against wear and the option to re-use the device. Based on our findings, we derive design recommendations for epidermal devices that combine tactile perception with device robustness

Fused Spectatorship: Designing Bodily Experiences Where Spectators Become Players

Spectating digital games can be exciting. However, due to its vicarious nature, spectators often wish to engage in the gameplay beyond just watching and cheering. To blur the boundaries between spectators and players, we propose a novel approach called ''Fused Spectatorship'', where spectators watch their hands play games by loaning bodily control to a computational Electrical Muscle Stimulation (EMS) system. To showcase this concept, we designed three games where spectators loan control over both their hands to the EMS system and watch them play these competitive and collaborative games. A study with 12 participants suggested that participants could not distinguish if they were watching their hands play, or if they were playing the games themselves. We used our results to articulate four spectator experience themes and four fused spectator types, the behaviours they elicited and offer one design consideration to support each of these behaviours. We also discuss the ethical design considerations of our approach to help game designers create future fused spectatorship experiences.Comment: This paper is going to be published at Annual Symposium on Computer-Human Interaction in Play (CHI PLAY) 202

Physical sketching tools and techniques for customized sensate surfaces

Sensate surfaces are a promising avenue for enhancing human interaction with digital systems due to their inherent intuitiveness and natural user interface. Recent technological advancements have enabled sensate surfaces to surpass the constraints of conventional touchscreens by integrating them into everyday objects, creating interactive interfaces that can detect various inputs such as touch, pressure, and gestures. This allows for more natural and intuitive control of digital systems. However, prototyping interactive surfaces that are customized to users' requirements using conventional techniques remains technically challenging due to limitations in accommodating complex geometric shapes and varying sizes. Furthermore, it is crucial to consider the context in which customized surfaces are utilized, as relocating them to fabrication labs may lead to the loss of their original design context. Additionally, prototyping high-resolution sensate surfaces presents challenges due to the complex signal processing requirements involved. This thesis investigates the design and fabrication of customized sensate surfaces that meet the diverse requirements of different users and contexts. The research aims to develop novel tools and techniques that overcome the technical limitations of current methods and enable the creation of sensate surfaces that enhance human interaction with digital systems.Sensorische Oberflächen sind aufgrund ihrer inhärenten Intuitivität und natürlichen Benutzeroberfläche ein vielversprechender Ansatz, um die menschliche Interaktionmit digitalen Systemen zu verbessern. Die jüngsten technologischen Fortschritte haben es ermöglicht, dass sensorische Oberflächen die Beschränkungen herkömmlicher Touchscreens überwinden, indem sie in Alltagsgegenstände integriert werden und interaktive Schnittstellen schaffen, die diverse Eingaben wie Berührung, Druck, oder Gesten erkennen können. Dies ermöglicht eine natürlichere und intuitivere Steuerung von digitalen Systemen. Das Prototyping interaktiver Oberflächen, die mit herkömmlichen Techniken an die Bedürfnisse der Nutzer angepasst werden, bleibt jedoch eine technische Herausforderung, da komplexe geometrische Formen und variierende Größen nur begrenzt berücksichtigt werden können. Darüber hinaus ist es von entscheidender Bedeutung, den Kontext, in dem diese individuell angepassten Oberflächen verwendet werden, zu berücksichtigen, da eine Verlagerung in Fabrikations-Laboratorien zum Verlust ihres ursprünglichen Designkontextes führen kann. Zudem stellt das Prototyping hochauflösender sensorischer Oberflächen aufgrund der komplexen Anforderungen an die Signalverarbeitung eine Herausforderung dar. Diese Arbeit erforscht dasDesign und die Fabrikation individuell angepasster sensorischer Oberflächen, die den diversen Anforderungen unterschiedlicher Nutzer und Kontexte gerecht werden. Die Forschung zielt darauf ab, neuartigeWerkzeuge und Techniken zu entwickeln, die die technischen Beschränkungen derzeitigerMethoden überwinden und die Erstellung von sensorischen Oberflächen ermöglichen, die die menschliche Interaktion mit digitalen Systemen verbessern

Design de tecnologias que vestem, revestem e se inserem no corpo humano: aceitação de tecnologias emergentes por jovens e pessoas com mais de 50 anos

Dissertação de mestrado em Design de Produto e ServiçosWearables é a designação atual de uma tipologia de produtos tecnológicos que se vestem. Muitos destes objetos complementam a indumentária pessoal e permitem interagir com outros produtos como dispositivos móveis e outros. Apesar do grande potencial que os wearables possuem – como por exemplo promover o exercício físico e a monitorização de condições de saúde, entre muitos outros – são poucos os casos em que são bem-sucedidos a longo prazo. Existem aspetos importantes a ter em conta no processo de design e desenvolvimento deste tipo de tecnologias emergentes. De forma a promover a sua aceitação, para além da estética, é fundamental considerar a experiência do utilizador – através do seu conforto, segurança, privacidade, entre outros fatores – e atender aos aspetos éticos relacionados, o que muitas vezes não acontece. Isto torna-se ainda mais pertinente à medida as inovações nesta área passam de tecnologias que se vestem para tecnologias que revestem e até tecnologias que se inserem no corpo humano. Este trabalho pretende explorar o potencial destas tecnologias, a partir de uma perspetiva de design centrado no utilizador, visando atender àquelas considerações e requisitos. Para um entendimento mais aprofundado e atual do universo de produtos emergentes neste domínio, foi realizada uma revisão do estado da arte. O levantamento resultante reuniu e analisou um conjunto de 23 soluções de interação de base tecnológica – umas em fase inicial e especulativa e outras já disponíveis no mercado – as quais foram organizadas em três categorias: as Vestíveis, as Revestíveis, e as Inseríveis. Foi, então, selecionada uma tecnologia de cada uma destas categorias para compreender e avaliar alguns aspetos relacionados com a sua aceitação, utilizando o Modelo de Aceitação de Tecnologias (TAM, o seu acrónimo inglês de uso comum) proposto por Davis (1989). A pesquisa, de natureza qualitativa, constou na realização de um questionário, dirigido por email a dois grupos de 20 participantes de faixas etárias diferentes: uma dos 16 a 19 anos e outra de pessoas com 50 ou mais anos. Os resultados, organizados pelas três tecnologias, demonstram que no geral o grupo jovem é mais recetivo do que o grupo mais velho quanto à utilidade percebida destas tecnologias, confirmando aquilo que se sugere na literatura relevante. Porém, para o exemplo de tecnologia inserível usado, os níveis de utilidade percebida foram semelhantes para os dois grupos. A discussão dos resultados incide sobre as nuances encontradas nos resultados, com relevo para as considerações feitas pelos participantes acerca das barreiras e dos potenciais benefícios destas tecnologias, de forma a perspetivar oportunidades de intervenção para o Design no desenvolvimento de tecnologias aceitáveis e inclusivas no futuro.Wearables is the current name given to a type of body-borne technology products. Many of these objects complement personal clothing and allow users to interact with other products such as mobile devices and others. Despite the great potential that wearables have – such as promoting physical exercise and monitoring health conditions, among many others – there are few cases in which they are successful in the long term. There are important aspects to take into account during the design and development process of this type of emerging technologies. To promote their acceptance, it is essential to consider the user experience beyond aesthetics – through comfort, safety, privacy, among other factors – and to attend to the related ethical aspects. This often does not happen. This becomes even more pertinent as innovations in this area move from technologies that are borne near the body to technologies that are borne on the body and even technologies that are inserted into the body. This work aims to explore the potential of these technologies, from a user-centred design perspective, with a view to responding to those considerations and requirements. For a more in-depth and current understanding of the universe of emerging products in this field, a review of the state of the art was undertaken. The resulting survey gathered and analysed a set of 23 technology-based interaction solutions – some in the initial and speculative phase and others already available on the market – which were organized into three categories: Near-body, On-body, and In-body. A technology from each of these categories was then selected to better understand and assess certain aspects related to their acceptance, using the Technology Acceptance Model (TAM) proposed by Davis (1989). The research comprised a qualitative questionnaire, which was sent by email to two groups of 20 participants from different age groups: one aged 16 to 19 and the other aged 50 or over. The results, organized according to the three technologies, show that, in general, the younger group is more receptive than the older group regarding the perceived usefulness of these technologies, confirming what is suggested in the relevant literature. However, for the insertable example used, the levels of perceived usefulness were similar for the two groups. The discussion of the results focuses on the nuances found in the results, highlighting the participants’ thoughts about the barriers and potential benefits of these technologies, in order to envision Design opportunities for the development of acceptable and inclusive technologies in the future