Recent research in e-textiles within the HCI community has shown a growing interest in sustainable prototyping to reduce the environmental impact of waste generated during e-textile fabrication. Meanwhile, the textile crafts community is exploring alternative sustainable materials. Despite shared goals, communication, knowledge exchange, and collaboration between these two disciplines remain limited. This work leverages HCI knowledge in open-source wet spinning and biofiber recipes to empower individuals in the textile crafts community to create functional biodegradable yarns for e-textile prototyping at home or in individual textile studios. To better understand their material exploration needs, we hosted a community-engaged workshop. Our findings emphasized the need for user-friendly machine designs, the value of hands-on learning, and the benefits of iterative exploration for examining the design affordances of material temporality. Through these efforts, we aim to promote sustainable making via community engagement and provide more widely available technical tools and curriculum resources for material-driven craft explorations.

We present EcoThreads, a sustainable e-textile prototyping approach for fabricating biodegradable functional threads. We synthesized two thread-based fabrication methods, wet spinning and thread coating, to fabricate functional threads from biomaterials or modify natural fiber to achieve conductive or interactive functionality. We built a wet spinning tool from a modified DIY syringe pump to spin biodegradable conductive threads. The conductive and interactive threads can be further integrated into textiles through weaving, knitting, embroidery, and braiding. We conducted a workshop study inviting e-textile practitioners to use the materials to fabricate e-textile swatches for transient use cases. The EcoThreads approach presents a path for individual creators to incorporate biodegradable material choices toward sustainable e-textile practices.

Hand edema, defined as swelling of the hands caused by excess fluid accumulation, is a pervasive condition affecting a person’s range of motion and functional ability. However, treatment strategies remain limited to time-consuming manual massage by trained therapists, deterring a widely accessible approach. We present KnitDema, a robotic textile device that allows sequential compression from distal to proximal finger phalanges for mobilizing edema. We machine-knit the device and integrate small-scale actuators to envelop granular body locations such as fingers, catering to the shape of the hand. In addition, the device affords customizable compression levels through the enclosed fiber-like actuators. We characterize compression parameters and simulate the shunting of edema through a mock fluid system. Finally, we conduct a case study to evaluate the feasibility of the device, in which five hand edema patients assess KnitDema. Our study provides insights into the opportunities for robotic textiles to support personalized rehabilitation.

Paper circuitry has been extensively explored by HCI researchers as a means of creating interactive objects. However, these approaches focus on creating desktop or handheld objects, and paper as a wearable material remains under-explored. We present SkinPaper, a fabrication approach using silicone-treated washi paper to weave lightweight and easy-to-fabricate on-skin interactions. We adopt techniques from paper weaving and basketry weaving practices to create paper-woven structures that can conform to the body. Our approach uses off-the-shelf materials to facilitate a highly customizable fabrication process. We showcase eight case studies to illustrate our approach’s two to three-dimensional forms. To understand the expressiveness of the design space, we conducted a workshop study in which weavers created paper-woven on-skin interactions. We draw insights from the studies to understand the opportunities for paper-woven on-skin interactions.

In this article, we present a mechanism and related path planning algorithm to construct light-duty barriers out of extruded, inflated tubes weaved around existing environmental features. Our extruded tubes are based on everted vine-robots and in this context, we present a new method to steer their growth. We characterize the mechanism in terms of accuracy resilience, and, towards their use as barriers, the ability of the tubes to withstand distributed loads. We further explore an algorithm which, given a feature map and the size and direction of the external load, can determine where and how to extrude the barrier. Finally, we showcase the potential of this method in an autonomously extruded two-layer wall weaved around three pipes. While preliminary, our work indicates that this method has potential for barrier construction in cluttered environments, e.g. shelters against wind or snow. Future work may show how to achieve tighter weaves, how to leverage weave friction for improved strength, how to assess barrier performance for feedback control, and how to operate the extrusion mechanism off of a mobile robot.

We propose Skinergy for self-powered on-skin input sensing, a step towards prolonged on-skin device usages. In contrast to prior on-skin gesture interaction sensors, Skinergy’s sensor operation does not require external power. Enabled by the triboelectric nanogenerator (TENG) phenomenon, the machine-embroidered silicone-textile composite sensor converts mechanical energy from the input interaction into electrical energy. Our proof-of-concept untethered sensing system measures the voltages of generated electrical signals which are then processed for a diverse set of sensing tasks: discrete touch detection, multi-contact detection, contact localization, and gesture recognition. Skinergy is fabricated with off-the-shelf materials. The aesthetic and functional designs can be easily customized and digitally fabricated. We characterize Skinergy and conduct a 10-participant user study to (1) evaluate its gesture recognition performance and (2) probe user perceptions and potential applications. Skinergy achieves 92.8% accuracy for a 11-class gesture recognition task. Our findings reveal that human factors (e.g., individual differences in skin properties, and aesthetic preferences) are key considerations in designing self-powered on-skin sensors for human inputs.

There has been a growing interest in developing and fabricating wearable sweat sensors in recent years, as sweat contains various analytes that can provide non-invasive indications of various conditions in the body. Although recent HCI research has been looking into wearable sensors for understanding health conditions, textile-based wearable sweat sensors remain underexplored. We present BioWeave, a woven thread-based sweat-sensing on-skin interface. Through weaving single-layer and multi-layer structures, we combine sweat-sensing threads with versatile fiber materials. We identified a design space consisting of colorimetric and electrochemical sensing approaches, targeting biomarkers including pH, glucose, and electrolytes. We explored 2D and 3D weaving structures for underexplored body locations to seamlessly integrate sweat-sensing thread into soft wearable interfaces. We developed five example applications to demonstrate the design capability offered. The BioWeave sensing interface can provide seamless integration into everyday textile-based wearables and offers the unobtrusive analysis of health conditions.

We present KnitSkin, a bio-inspired sleeve that can traverse diverse cylindrical terrains, ranging from a user’s forearm at a wearable scale, to pipes and tree branches at an environmental scale. Fabricated with a machine knitted substrate, the sleeve configures a stepped array of knitted scales that exhibit anisotropic friction. Coupled with the extension of actuators enclosed in the sleeve, the scales enable effective directional locomotion on cylindrical surfaces with varying slopes, textures, and curvatures. KnitSkin’s substrates are characterized by scales whose geometries and materials can be fine-tuned and channels that can accommodate diverse actuators. We introduce the design elements of KnitSkin in which we characterize a series of substrate parameters and their resulting anisotropic behaviors. In evaluating the locomotion, we examine the variables associated with the surface and actuator characteristics. KnitSkin obtains diverse applications across different scales, including wearable interfaces, industrial pipe-monitoring, to agricultural robots.

We present Patch-O, a novel deformable interface devised as a woven patch that enables diverse movement-based interactions adaptive to garments or on-skin wearing. Patch-O interfaces are uniquely detachable and relocatable soft actuation units that can be sewn or attached to clothing or skin at various locations. To optimize the morphing effect while preserving a slim form factor, we introduce a construction approach that integrates actuators at a structural level and varies the texture and stiffness of the woven substrate locally. We implement three basic actuation primitives, including bending, expanding, and shrinking, and experiment with aggregation parameters to exhaustively extend the design space. A final workshop study inviting textile practitioners to create personalized designs of Patch-O provides insights into the expressiveness of the approach for wearable interactions. We conclude with three applications inspired by users’ designs and showcase the aesthetic and functional usages enabled by the deformable woven patches.

Robots are typically designed as occupants of rooms, adapting to, and navigating within them. “Robot surfaces,” an emerging robot typology, are not occupants of but integral with rooms, physically shaping rooms to support human activity. We report on an advancement of robot surfaces formed by weaving McKibben Pneumatic Air Muscles that, when actuated, morph a 2D planar surface to generate 3D geometries including a “spherical cap.” Following our foundational study at different scales with different materials, we developed a full-scale prototype that offers an intimate and private space for people meeting in open plan environments. We report on our research, focusing on a design case, and validate the full-scale prototype as compared to our Non-Uniform Rational B-Splines (NURBS) model for three useful configurations. Our quantitative and qualitative results suggest that our robot surface can support human activity as envisioned. This research contributes foundational understanding of an emerging category of robotics from which our team and peers can build.

On-skin interfaces demonstrate great potential given their direct skin contact; however, conducting field studies of these devices outside of laboratories and in real settings remains a challenge. We conduct a research-through-design investigation using an extended woven practice for fabricating fully-integrated and untethered multi-sensor on-skin systems that are resilient, versatile, and capable of field deployment. We designed, implemented, and deployed a woven on-skin index-finger and thumb-based inertial measurement unit (IMU) sensing system for multi-hour use as a technology probe to understand the social, technical, and design facets towards moving integrated on-skin systems into a wearer’s daily life. Further, we integrate a woven NFC coil into the IMU on-skin system, which is wirelessly powered by a smartwatch substitute, signifying the potential of our woven approach for developing wirelessly powered on-skin systems for longer-term continuous wear. Our investigation and the lessons learned shed light on the opportunities for designing on-skin systems for everyday wear.

We present KnitDermis, on-body interfaces that deliver expressive non-vibrating mechanotactile feedback on the wearer’s body. Fabricated through machine knitting, they embed shape-memory alloy micro-springs in knitted channels, which deliver tactile sensations on the skin when activated. KnitDermis interfaces take advantage of machine knitting’s shaping properties which allow it to generate slim, stretchable, and versatile forms that can conform to underexplored body locations, such as protruded joints and convex body locations. We introduce a fabrication approach and a series of case studies to design a wide range of form factors, textures, and tactile patterns, including compression, pinching, brushing, and twisting. We conduct a user study to elicit KnitDermis’ effectiveness and wearability on diverse body locations and engage users to unpack envisioned use cases and perceptions towards the interfaces. We draw insights from our extensive research-through-design investigations on the potential of knitting as a soft approach for close-body and expressive tactile interfaces.

Weaving as a craft possesses the structural, textural, aesthetic, and cultural expressiveness for creating a diversity of soft, wearable forms that are capable of technological integration. In this paper, we extend the woven practice for crafting on-skin interfaces, exploring the potential to "weave a second skin." Weaving incorporates circuitry in the textile structure, which, when extended to on-skin interface fabrication, allows for electrical connections between layers while maintaining a slim form. Weaving also supports multi-materials integration in the structure itself, offering richer materiality for on-skin devices. We present the results of extensive design experiments that form a design space for adapting weaving for on-skin interface fabrication. We introduce a fabrication approach leveraging the skin-friendly material of PVA, which enables on-skin adherence, and a series of case studies illustrating the functional and design potential of the approach. To understand the feasibility of on-skin wear, we conducted a user study on device wearability. To understand the expressiveness of the design space, we conducted a workshop study in which textiles practitioners created woven on-skin interfaces. We draw insights from this to understand the potential of adapting weaving for crafting on-skin interfaces.

On-skin displays are emerging as a wearable form factor for the display of information; however, the perception of using such devices in public could determine whether they are eventually adopted or rejected. This study investigated the means by which on-skin notification displays are perceived by the general public. We adopted a mixed-methods approach to the analysis of results from an online survey (n = 254) and in-lab interviews (n = 36) pertaining to the novel form factor, device materiality, and envisioned use cases. The study was conducted in the US and Taiwan in order to examine cross-cultural attitudes toward device usage. The results of this structured examination provide valuable insights into the design of on-skin notification displays for everyday use across cultures.

Wearable devices have evolved towards intrinsic human augmentation, unlocking the human skin as an interface for seamless interaction. However, the non-traditional form factor of these on-skin interfaces, as well as the gestural interactions performed on them may raise concerns for public wear. These perceptions will influence whether a new form of technology will eventually be accepted, or rejected by society. Therefore, it is essential for researchers to consider the societal implications of device design. In this paper, we investigate the third person perceptions of a user's interactions with an on-skin touch sensor. Specifically, we examine social perceptions towards the placement of the on-skin interface in different body locations, as well as gestural interactions performed on the device. The study was conducted in the United States and Taiwan to examine cross-cultural attitudes towards device usage. The results of this structured examination offer insight into the design of on-skin interfaces for public use.

SkinMorph is an on-skin interface which can selectively transition between soft and rigid states to serve as a texture-tunable wearable skin output. This texture change is made possible through the material design of smart hydrophillic gels. These gels are soft in resting state, yet when activate by heat (>36°C), they generate a micro-level structural change which results in observable stiffening. These gels are encapsulated in thin silicone patterned with resistive wires through a sew-and-transfer fabrication approach. We demonstrate application examples using the texture-tunable skin overlay as wearable, interactive protection for scenarios including: a carpal tunnel splint for rehabilitation, a protective layer for joints when engaging in high impact activities, and foot pads when wearing uncomfortable shoes. Our evaluation shows that the gel is 10 times stiffer when activated, and that users find the device skin-conformable.

Jewelry and accessories have long been objects for decorating the human body; however they remain static and non-interactive. This work explores opportunities for accessory-like kinetic wearables and their association with individual style. We developed Kino, a kinetic accessory system which enables both aesthetic and functional clothing-specific design possibilities. We engaged both fashion designers and every-day users to unpack envisioned use cases and perceptions of the system. Participants viewed the devices not as gadgets but as companions due to their close proximity to the body. They envisioned a wide range of usage scenarios, highlighting the complexity of mobility in relation to personal style. We observe how mobility offers opportunities for fluid representations of self, which is unachievable though static clothing and accessories. We also outline how personalized aesthetics is important for the meaning making of novel on-body devices.

We introduce Rovables, a miniature robot that can move freely on unmodified clothing. The robots are held in place by magnetic wheels, and can climb vertically. The robots are untethered and have an onboard battery, microcontroller, and wireless communications. They also contain a low-power localization system that uses wheel encoders and IMU, allowing Rovables to perform limited autonomous navigation on the body. In the technical evaluations, we found that Rovables can operate continuously for 45 minutes and can carry up to 1.5N. We propose an interaction space for mobile on-body devices spanning sensing, actuation, and interfaces, and develop application scenarios in that space. Our applications include on-body sensing, modular displays, tactile feedback and interactive clothing and jewelry.

We present NailO, a nail-mounted gestural input surface. Using capacitive sensing on printed electrodes, the interface can distinguish on-nail finger swipe gestures with high accuracy (>92%). NailO works in real-time: we miniaturized the system to fit on the fingernail, while wirelessly transmitting the sensor data to a mobile phone or PC. NailO allows one-handed and always-available input, while being unobtrusive and discrete. Inspired by commercial nail stickers, the device blends into the user's body, is customizable, fashionable and even removable. We show example applications of using the device as a remote controller when hands are busy and using the system to increase the input space of mobile phones.

clayodor (\klei-o-dor\) is a clay-like malleable material that changes smell based on user manipulation of its shape. This work explores the tangibility of shape changing materials to capture smell, an ephemeral and intangible sensory input. We present the design of a proof-of-concept prototype, and discussions on the challenges of navigating smell though form.

We explore creating objects for expressive communication in the workspace. As an initial step, we created MugShots, a coffee mug with a wireless OLED display that switches between public and private social interaction modes. Targeted for the workplace, MugShots is an intimate communication device in the personal office space, yet alternates to become a social catalyst to trigger conversation when brought to public areas. We present a prototype of MugShots along with a 21-person study, providing initial discussions and insight on designing objects for communication.

SensorTape is a modular and dense sensor network in a form factor of a tape. SensorTape is composed of interconnected and programmable sensor nodes on a flexible electronics substrate. Each node can sense its orientation with an inertial measurement unit, allowing deformation self-sensing of the whole tape. Also, nodes sense proximity using time-of-flight infrared. We developed network architecture to automatically determine the location of each sensor node, as SensorTape is cut and rejoined. Also, we made an intuitive graphical interface to program the tape. Our user study suggested that SensorTape enables users with different skill sets to intuitively create and program large sensor network arrays. We developed diverse applications ranging from wearables to home sensing, to show low deployment effort required by the user. We showed how SensorTape could be produced at scale using current technologies and we made a 2.3-meter long prototype.

This study proposes a phone-based system to detect the gait anomalies of a person waking under the influence of alcohol. This phone-based system can sense a person's alcohol usage and record the location/time context. This data can help identify problem drinking behaviors, such as drinking before work or before driving.

To promote energy-saving behavior, disaggregating electricity usage is critical for increasing consumer awareness of energy usage behavior. This study proposes HeatProbe, a thermal-based power meter system that uses thermal imaging to track disaggregated appliance usage. We have designed, prototyped, and tested the HeatProbe system. Results show that HeatProbe successfully senses individual appliance operating durations with an average error of 125.03 seconds, achieving 80.2% appliance power accounting accuracy in different appliance usage scenarios.