Adding electronics to textiles can be time-consuming and requires technical expertise. We introduce SensorSnaps, low-power wireless sensor nodes that seamlessly integrate into caps of fabric snap fasteners. SensorSnaps provide a new technique to quickly and intuitively augment any location on the clothing with sensing capabilities. SensorSnaps securely attach and detach from ubiquitous commercial snap fasteners. Using inertial measurement units, the SensorSnaps detect tap and rotation gestures, as well as track body motion. We optimized the power consumption for SensorSnaps to work continuously for 45 minutes and up to 4 hours in capacitive touch standby mode. We present applications in which the SensorSnaps are used as gestural interfaces for a music player controller, cursor control, and motion tracking suit. The user study showed that SensorSnap could be attached in around 71 seconds, similar to attaching off-the-shelf snaps, and participants found the gestures easy to learn and perform. SensorSnaps could allow anyone to effortlessly add sophisticated sensing capacities to ubiquitous snap fasteners.

Biosensing displays, increasingly enrolled in emotional reflection, promise authoritative insight by presenting users' emotions as discrete categories. Rather than machines interpreting emotions, we sought to explore an alternative with emotional biosensing displays in which users formed their own interpretations and felt comfortable critiquing the display. So, we designed, implemented, and deployed, as a technology probe, an emotional biosensory display: Ripple is a shirt whose pattern changes color responding to the wearer's skin conductance, which is associated with excitement. 17 participants wore Ripple over 2 days of daily life. While some participants appreciated the 'physical connection' Ripple provided between body and emotion, for others Ripple fostered insecurities about 'how much' feeling they had. Despite our design intentions, we found participants rarely questioned the display's relation to their feelings. Using biopolitics to speculate on Ripple's surprising authority, we highlight ethical stakes of biosensory representations for sense of self and ways of feeling.

Conventionally, keys on a physical keyboard have only two states: "released'' and "pressed''. As such, various techniques, such as hotkeys, are designed to enhance the keyboard expressiveness. Realizing that user inevitably perform touch actions during keystrokes, we propose GestAKey, leveraging location and motion of the touch on individual keycaps to augment the functionalities of existing keystrokes. With a log study, we collected touch data for both normal usage (typing and hotkeys) and while performing touch gestures (location and motion), which are analyzed to assess the viability of augmenting keystrokes with simultaneous gestures. A controlled experiment was conducted to compare GestAKey with existing keyboard interaction techniques, in terms of efficiency and learnability. The results show that GestAKey has comparable performance with hotkey. We further discuss the insights of integrating such touch modality into existing keyboard interaction, and demonstrate several usage scenarios.

Beyond phones, watches, and activity tracking devices, a new ecosystem of functional and fashionable wearable technologies can easily, safely, and economically be designed, prototyped, and integrated directly on the body. In this paper, we present AlterNail, a fingernail form factor, ambient, low-power, stateful, wireless, dynamic display with onboard vibrational sensing. AlterNail integrates a batteryless design using inductive coupling with e-ink technology to enable both quick dynamic and long-term static fingernail based visual designs without the need for power. We also detail the use of simple vibrational signals to uniquely identify everyday objects as they are handled using AlterNails. The intentionally limited interactional functionality of AlterNails, coupled with the rich personal and dynamic expressive potential, combine to present a compelling range of opportunities for designers of new interactive wearable technologies. We detail a range of practical and playful applications using this technology.

This paper explores the social meaning of clothing-based displays of biosignals. How do friends make sense of their own and each other's skin conductance display in the context of a conversation? We developed Hint, a dynamic thermochromic t-shirt whose ambiguous pattern changes color when its wearer's skin conductance increases, an indication of sudden arousal. We investigated how pairs of friends each wearing the shirt conversed and interpreted the display. Participants shared a broad range of interpretations; e.g., joy and embarrassment were associated with an increase in skin conductance. Additionally, participants expressed desires for their skin conductance display to help validate their feelings and show emotional engagement with others. We explore ambiguity in the context of clothing-based information displays and discuss how skin conductance display became part of social performance in our study. From there, we suggest framing biosignals as social cues along with facial expression, gestures, etc., and begin to question what design territories this might uncover.