The relationship between the Nigerian police and citizens is strained, hindering the co-design of conventional technologies to enhance community policing (CP) initiatives, hence the imperative to involve both in the design of a usable CP technology that can carter for their needs.Our preliminary findings indicate that Nigerian citizens are reluctant to participate in co-design activities with the police due to discomfort and fear, which could potentially bias the design outcomes.Designing a CP technology with such stakeholders is crucial, but a new challenge for the Human Computer Interaction (HCI) community, as no existing framework has addressed it.We introduce Conflict Sensitive Design (CSD), a co-design approach that leverages mediation techniques (tension reduction, leveling, common ground reminder, separated meetings, formalizing agreements) to iteratively collect, analyze, and reconcile design inputs, ensuring that the final design is usable for CP enhancement.Our case application worked in CP technology requirements gathering with Nigerian CP stakeholders, and it could be extended to related HCI contexts.We present a structured approach to conflict resolution in co-design processes, and discuss the lessons learned as a spotlight to guide other designers in related contexts.

Indoor photovoltaic materials are novel low-cost light sensors that can be flexible, decorative, self-powered, and battery-free, and can be embedded in various surfaces throughout the home. They offer a unique opportunity for contextual control of multiple different devices in a smart home using guessable and favorite gestures. Currently available gesture vocabularies are survey-based and sensor-agnostic, but still require experimental validation. Therefore, we present experimentally generated and validated original gesture vocabularies using two user elicitation methods, the guessability and production methods, for such sensors. The capabilities of the sensor was used to prime participants for design thinking to multi-control smart home devices. We provide guidelines for designing gesture vocabularies using the two elicitation methods and report on their similarities and differences. The methodological findings and experimentally validated gesture sets would inform HCI researchers in the design of user-elicited interactions for such versatile light or electromagnetic field sensors and similar gesture-driven applications.

Social robots such as companion or pet robots are increasingly being used for older adults’ mental well-being. Pet robot touch interactions could have positive effects on well-being similar to those observed in natural interactions with real animals. Designing pet robot interactions for an elderly family member with young adults could create gratitude and memory, thereby improving attitudes towards social robots. To this end, we conducted a preliminary user identification study with five young adults to determine their elderly family members’ preferences for sound/voice responses to touch inputs, using JoyForAll pet robots as technology probes. We report users’ likability of the preferred positive touch interactions, themes that emerged from the think-aloud design for touch interactions, and agreement rates of the robots’ sound/voice responses.

We present a methodology for co-designing a human-agent interface and a case study in online grooming detection for incorporating multiple-stakeholders perspectives into the design of human-agent platforms, with the goal of establishing a common dialogue between the stakeholders. We propose that iterative co-design techniques staged in a provotypical fashion could successfully capture and overcome tensions between stakeholders perspectives on how human-agent interactions ought to be manifested. Our initial work found that our iterative co-design framework could be successful in resolving these tensions. However, multiple design iterations that focus on finding compromises between stakeholders can lead to acceptance of novel interaction designs.

In recent times, many studies have identified trust as a propeller of community policing for enhancing security and safety. However, this essential aspect of community policing has not been properly classified. This has resulted in ambiguity and misunderstanding of the trust being referred to in community policing context. To cover this gap, this research carried out a systematic review of three scientific journal databases using PRISMA protocol which produced 16 document results after excluding 20,270 studies that didn't meet our criteria. Consequently, community policing trusts were identified and categorized in terms of technology-based trust (TbT), Human-to-Human Trust (HtHT) and Trust for both humans and technology (TbHT). Also, the research further established three themes for improving trust in community policing. In the end, this study has established the significant effect of different categories of trust as it supports community policing. More so, while this research informs on work that has been done on trust and community policing overtime, it provides distinct and comparable terms for future Human Computer Interaction (HCI) research.

Mental health challenges became more prevalent during the COVID-19 pandemic, especially among older adults. Consequently, we witnessed an uptake of new technologies, including social robots to address these challenges. However, we observed limited inclusion of older adults in the design process to design these technologies to cater user needs during the pandemic. To address this gap, we conducted a co-design workshop with 17 older adults and explored their emotional challenges after the COVID-19 pandemic. They evaluated the current social robot designs available in the literature and elicited the design preferences for a social robot to address their current emotional challenges. Our results based on thematic analysis show that the impact of the pandemic on older adults’ emotional challenges is persisting, and the companionship of a social robot is preferred to enhance their mental well-being. We also show that older adults preferred an animal-like robot design embodied with soft skin possessing a medium size. These findings highlighted older adults’ design choices of a social robot and affirmed their potential to support older adults’ mental well-being.

What do pedestrian crossings, ATMs, elevators and ticket machines have in common? These are just a few of the ubiquitous yet essential elements of public-space infrastructure that rely on physical buttons or touchscreens; common interactions that, until recently, were considered perfectly safe to perform. This work investigates how we might integrate touchless technologies into public-space infrastructure in order to minimise physical interaction with shared devices in light of the ongoing COVID-19 pandemic. Drawing on an ethnographic exploration into how public utilities are being used, adapted or avoided, we developed and evaluated a suite of technology probes that can be either retrofitted into, or replace, these services. In-situ community deployments of our probes demonstrate strong uptake and provide insight into how hands-free technologies can be adapted and utilised for the public domain; and, in turn, used to inform the future of walk-up-and use public technologies.

Many of us daily encounter shadow and reflected light patterns alongside macro-level changes in ambient light levels. These are caused by elements—opaque objects, glass, mirrors, even clouds—in our environment interfacing with sunlight or artificial indoor lighting. Inspired by these phenomena, we explored ways of creating digitally-supported displays that use light, shade and reflection for output and harness the energy they need to operate from the sun or indoor ambient light. Through a set of design workshops we developed exemplar devices: SolarPix, ShadMo and GlowBoard. We detail their function and implementation, as well as evidencing their technical viability. The designs were informed by material understandings from the Global North and Global South and demonstrated in a cross-cultural workshop run in parallel in India and South Africa where community co-designers reflected on their uses and value given lived experience of their communication practices and unreliable energy networks.

Working with emergent users in two of Mumbai’s slums, we explored the value and uses of photovoltaic (PV) self-powering digital materials. Through a series of co-design workshops, a diary study and responses by artists and craftspeople, we developed the PV-Pix concept for inter-home connections. Each PV-Pix element consists of a deformable energy harvesting material that, when actuated by a person in one home, changes its physical state both there and in a connected home. To explore the concept we considered two forms of PV-Pix: one uses rigid materials and the other flexible ones. We deployed two low-fidelity prototypes, each constructed of a grid of one PV-Pix type, in four slum homes over a four week period to further understand the usability and uses of the materials, eliciting interesting inter-family communication practices. Encouraged by these results we report on a first-step towards working prototypes and demonstrate the technical viability of the approach.

We present Flowcuits, a DIY fabrication method to prototype tangible, interactive and functional electrical components by manipulating liquid metals. The prototypes afford both physical and visual interactions to demonstrate the inner working mechanics of fundamental electronic elements, which enables tangible and playful learning. The fabrication process follows simple imprinting and sealing of fluidic circuits with a 3D-printed stamp on an accessible moldable-substrates such as ‘Blu Tack’. Utilizing conductive gallium indium liquid metal, we demonstrated interactive and re-configurable electronic components such as switches, variable resistors, variable capacitors, logic gates and pressure sensors. In this paper, we present the design analogy of Flowcuits, DIY fabrication approach including a parametric 3D stamp design toolkit and results from a technical evaluation. The stamps are printed with a low-cost 3D printer and all the materials are inexpensive and reusable, enabling Flowcuits to be easily used without any advanced lab facilities.

Recently, people prefer to read books via a combination of formats - E-Books along with printed books. We conducted a scoping survey and a lab-study which informed various inhibiting factors associated with switching between formats to conveniently use multiple formats. To improve the switching experience, we present Digital Bookmark that synchronises the current page location digitally between both printed and e-books. The page number of the printed book is electronically read using a conductive tag and transmitted to the e-book via the internet. The current location on the e-book is converted to the corresponding page number of the printed book and presented on the display of the Digital Bookmark. We present the results of a controlled lab-study to assess the parameters of switching between printed and electronic books. The initial feedback from a local reading group suggests that our Digital Bookmark would encourage multi-format reading and improve their user experience.

The interactive, digital future with its seductive vision of Internet-of-Things connected sensors, actuators and displays comes at a high cost in terms of both energy demands and the clutter it brings to the physical world. But what if such devices were made of materials that enabled them to self-power their interactive features? And, what if those materials were directly used to build aesthetically pleasing environments and objects that met practical physical needs as well as digital ones? In this paper we introduce PV-Tiles ? a novel material that closely couples photovoltaic energy harvesting and light sensing materials with digital interface components. We consider potential contexts, use-cases and light gestures surfaced through co-creation workshops; and, present initial technological designs and prototypes. The work opens a new set of opportunities and collaborations between HCI and material science, stimulating technical and design pointers to accommodate and exploit the material's properties.

Multiple fingers are often used for efficient interaction with handheld computing devices. Currently, any tactile feedback provided is felt on the finger pad or the palm with coarse granularity. In contrast, we present a new tactile feedback technique, Active PinScreen, that applies localised stimuli on multiple fingers with fine spatial and temporal resolution. The tactile screen uses an array of solenoid-actuated magnetic pins with millimetre scale form-factor which could be deployed for back-of-device handheld use without instrumenting the user. As well as presenting a detailed description of the prototype, we provide the potential design configurations and the applications of the Active PinScreen and evaluate the human factors of tactile interaction with multiple fingers in a controlled user evaluation. The results of our study show a high recognition rate for directional and patterned stimulation across different grip orientations as well as within- and between- fingers. We end the paper with a discussion of our main findings, limitations in the current design and directions for future work.

This paper explores the use of conversational speech question and answer systems in the challenging context of public spaces in slums. A major part of this work is a comparison of the source and speed of the given responses; that is, either machine-powered and instant or human-powered and delayed. We examine these dimensions via a two-stage, multi-sited deployment. We report on a pilot deployment that helped refine the system, and a second deployment involving the installation of nine of each type of system within a large Mumbai slum for a 40-day period, resulting in over 12,000 queries. We present the findings from a detailed analysis and comparison of the two question-answer corpora; discuss how these insights might help improve machine-powered smart speakers; and, highlight the potential benefits of multi-sited public speech installations within slum environments.

Touchscreens are the predominant medium for interactions with digital services; however, their current fixed form factor narrows the scope for rich physical interactions by limiting interaction possibilities to a single, planar surface. In this paper we introduce the concept of PickCells, a fully re-configurable device concept composed of cells, that breaks the mould of rigid screens and explores a modular system that affords rich sets of tangible interactions and novel across-device relationships. Through a series of co-design activities -- involving HCI experts and potential end-users of such systems -- we synthesised a design space aimed at inspiring future research, giving researchers and designers a framework in which to explore modular screen interactions. The design space we propose unifies existing works on modular touch surfaces under a general framework and broadens horizons by opening up unexplored spaces providing new interaction possibilities. In this paper, we present the PickCells concept, a design space of modular touch surfaces, and propose a toolkit for quick scenario prototyping.

Current haptic feedback techniques on handheld devices are applied to the finger pad or the palm of the user. These state-of-the-art approaches are coarse-grained and tend to be intrusive, rather than subtle. In contrast, we present a new feedback technique that applies stimuli around the periphery of the finger pulp, demonstrating how this can provide rich, nuanced haptic information. We use a reconfigurable haptic device employing a ferromagnetic marble for back-of-the device handheld use, which, for the first time, probes, without instrumenting the user, the periphery of the distal phalanx with localised stimulation. We present the design-space afforded by this new technique and evaluate the human-factors of finger-peripheral touch interaction in a controlled user-study. We report results with marbles of different diameters, speeds and a combination of poking, lateral vibration and patterns; present the resulting design guidelines for finger-periphery haptic feedback; and, illustrate its potential with use case scenarios.

We present Tangible Drops, a visio-tactile display that for the first time provides physical visualization and tactile feedback using a planar liquid interface. It presents digital information interactively by tracing dynamic patterns on horizontal flat surfaces using liquid metal drops on a programmable electrode array. It provides tactile feedback with directional information in the 2D vector plane using linear locomotion and/or vibration of the liquid metal drops. We demonstrate move, oscillate, merge, split and dispense-from-reservoir functions of the liquid metal drops by consuming low power (450 mW per electrode) and low voltage (8--15 V). We report on results of our empirical study with 12 participants on tactile feedback using 8 mm diameter drops, which indicate that Tangible Drops can convey tactile sensations such as changing speed, varying direction and controlled oscillation with no visual feedback. We present the design space and demonstrate the applications of Tangible Drops, and conclude by suggesting potential future applications for the technique.

Digital painting is an increasingly popular medium of expression for many artists, yet when compared to its traditional equivalents of physical brushes and viscous paint it lacks a dimension of tangibility. We conducted observations and interviews with physical and digital artists, which gave us a strong understanding of the types of interactions used to create both physical and digital art, and the important role tangibility plays within these experiences. From this, we developed a unique liquid-like tangible display for mobile, digital colour mixing. Using a chemical hydrogel that changes its viscosity depending on temperature, we are able to create some resemblances to the feeling of mixing paint with a finger. This paper documents the information gathered from working with artists, how this process informed the development of a mobile painting attachment, and an exploration of its capabilities. After returning with our prototype, we found that it provided artists with sensations of oil and acrylic paint mixing and also successfully mimicked how paints are laid out on a paint palette.

Many users value the ability to have quick and frequent sight of their mobiles when in public settings. However, in doing so, they expose themselves to potential risks, ranging from being targets of robbery to the more subtle social losses through being seen to be rude or inattentive to those around them. In nature, some animals can blend into their environments to avoid being eaten or to reduce their impact on the ecosystem around them. Taking inspiration from these evolved systems we investigate the notion of chameleon approaches for mobile interaction design. Our probes were motivated, inspired and refined through extended interactions with people drawn from contexts with differing ranges of security and privacy concerns. Through deployments on users' own devices, our prototypes show the value of the concept. The encouraging results motivate further research in materials and form factors that can provide more effective automatic plain-sight hiding.

Many finger sensing input devices now support proximity input, enabling users to perform in-air gestures. While near-surface interactions increase the input vocabulary, they lack tactile feedback, making it hard for users to perform gestures or to know when the interaction takes place. Sparkle stimulates the fingertip with touchable electric arcs above a hover sensing device to give users in-air tactile or thermal feedback, sharper and more feelable than acoustic mid-air haptic devices. We present the design of a high voltage resonant transformer with a low-loss soft ferrite core and self-tuning driver circuit, with which we create electric arcs 6 mm in length, and combine this technology with infrared proximity sensing in two proof-of-concept devices with form factor and functionality similar to a button and a touchpad. We provide design guidelines for Sparkle devices and examples of stimuli in application scenarios, and report the results of a user study on the perceived sensations. Sparkle is the first step towards providing a new type of hover feedback, and it does not require users to wear tactile stimulators.

Our work presents a method to use paper as an input device while reading on a mobile device, where the user turns a physical page in the real world in order to turn a page in the digital world. Our goal in this work is to replicate the feedback and affordances one would receive from a printed book on a mobile device, where to fully replicate the reading experience the user would need to turn pages as they would naturally with a printed book. Through a small study we discovered a number of ways that pages are often turned and these techniques became vital to the project. We describe a prototype device which uses paper as an input device with transparent electrodes and bend sensors embedded to pages, so that the turning and bending of pages can be digitally detected and addressed. The prototype is able to detect the page turns and bends made by the user and the state of each page.

In this paper, we demonstrate a method for the dynamic 2D transformation of liquid matter and present unique organic animations based on spatio-temporally controlled electric fields. In particular, we deploy a droplet of liquid metal (Gallium indium eutectic alloy) in a 7x7 electrode array prototype system, featuring an integrated image tracking system and a simple GUI. Exploiting the strong dependance of EGaIn's surface tension on external electric voltages, we control multiple electrodes dynamically to manipulate the liquid metal into a fine-grained desired shape. Taking advantage of the high conductivity of liquid metals, we introduce a shape changing, reconfigurable smart circuit as an example of unique applications. We discuss system constraints and the overarching challenge of controlling liquid metals in the presence of phenomena such as splitting, self-electrode interference and finger instabilities. Finally, we reflect on the broader vision of this project and discuss our work in the context of the wider scope of programmable materials.

We present a programmable liquid matter which can dynamically transform its 2D shape into a variety of forms and present unique organic animations based on spatio-temporally controlled electric fields. We deployed a EGaIn (Gallium indium eutectic alloy) liquid metal as our smart liquid material since it features a superior electric conductivity in spite of a liquid state and presents a high dynamic range of surface tension and 2D area controlled by applied voltage strength and polarity. Our proposed liquid metal shape and motion control algorithms with dynamically patterned electric fields realize path tracing organic animation. We demonstrate an interactive 7x7 electrode array control system with a computer vision based GUI system to enable novice users to physically draw alphabet letters and 2D shapes by unique animatronics of liquid metals.

We present TableHop, a tabletop display that provides controlled self-actuated deformation and vibro-tactile feedback to an elastic fabric surface while retaining the ability for high-resolution visual projection. The surface is made of a highly stretchable pure spandex fabric that is electrostatically actuated using electrodes mounted on its top or underside. It uses transparent indium tin oxide electrodes and high-voltage modulation to create controlled surface deformations. Our setup actuates pixels and creates deformations in the fabric up to +/- 5 mm. Since the electrodes are transparent, the fabric surface functions as a diffuser for rear-projected visual images, and avoid occlusion by users or actuators. Users can touch and interact with the fabric to experience expressive interactions as with any fabric based shape-changing interface. By using frequency modulation in the high-voltage circuit, it can also create localized tactile sensations on the user's fingertip when touching the surface. We provide simulation and experimental results for the shape of the deformation and frequency of the vibration of the surface. These results can be used to build prototypes of different sizes and form-factors. We present a working prototype of TableHop that has 30x40 cm2 surface area and uses a grid of 3x3 transparent electrodes. It uses a maximum of 9.46 mW and can create tactile vibrations of up to 20 Hz. TableHop can be scaled to make large interactive surfaces and integrated with other objects and devices. TableHop will improve user interaction experience on 2.5D deformable displays.

We present JOLED, a mid-air display for interactive physical visualization using Janus objects as physical voxels. The Janus objects have special surfaces that have two or more asymmetric physical properties at different areas. In JOLED, they are levitated in mid-air and controllably rotated to reveal their different physical properties. We made voxels by coating the hemispheres of expanded polystyrene beads with different materials, and applied a thin patch of titanium dioxide to induce electrostatic charge on them. Transparent indium tin oxide electrodes are used around the levitation volume to create a tailored electric field to control the orientation of the voxels. We propose a novel method to control the angular position of individual voxels in a grid using electrostatic rotation and their 3D position using acoustic levitation. We present a display in which voxels can be flipped independently, and two mid-air physical games with a voxel as the playable character that moves in 3D across other physical structures and rotates to reflect its status in the games. We demonstrate a voxel update speed of 37.8 ms/flip, which is video-rate.

The form factors of displays using fog or water surface are limited by our ability to control the non-solid substances used as the diffuser. We propose a charging technique for polar aerosols (e.g., mist or fog) that allows control of the shape and trajectory of such non-solid diffusers using electric fields. We report experiments that allowed us to design a charging mechanism that produces charged fog aerosols with homogeneous electrical mobility. We illustrate our idea by demonstrating how electric fields can be used to control the shape of a fog display and the trajectory of a bubble display.