Challenge is the core element of digital games. The wide spectrum of physical, cognitive, and emotional challenge experiences provided by modern digital games can be evaluated subjectively using a questionnaire, the CORGIS, which allows for a post hoc evaluation of the overall experience that occurred during game play. Measuring this experience dynamically and objectively, however, would allow for a more holistic view of the moment-to-moment experiences of players. This study, therefore, explored the potential of detecting perceived challenge from physiological signals. For this, we collected physiological responses from 32 players who engaged in three typical game scenarios. Using perceived challenge ratings from players and extracted physiological features, we applied multiple machine learning methods and metrics to detect challenge experiences. Results show that most methods achieved a …

As touch interactions become ubiquitous in the field of human computer interactions, it is critical to enrich haptic feedback to improve efficiency, accuracy, and immersive experiences. This paper presents HapTag, a thin and flexible actuator to support the integration of push button tactile renderings to daily soft surfaces. Specifically, HapTag works under the principle of hydraulically amplified electroactive actuator (HASEL) while being optimized by embedding a pressure sensing layer, and being activated with a dedicated voltage appliance in response to users’ input actions, resulting in fast response time, controllable and expressive push-button tactile rendering capabilities. HapTag is in a compact formfactor and can be attached, integrated, or embedded on various soft surfaces like cloth, leather, and rubber. Three common push button tactile patterns were adopted and implemented with HapTag. We validated the feasibility and expressiveness of HapTag by demonstrating a series of innovative applications under different circumstances.

The imitation of pain sensation in Virtual Reality is considered valuable for safety education and training but has been seldom studied. This paper presents Douleur, a wearable haptic device that renders intensity-adjustable pain sensations with chemical stimulants. Different from mechanical, thermal, or electric stimulation, chemical-induced pain is more close to burning sensations and long-lasting. Douleur consists of a microfluidic platform that precisely emits capsaicin onto the skin and a microneedling component to help the stimulant penetrate the epidermis layer to activate the trigeminal nerve efficiently. Moreover, it embeds a Peltier module to apply the heating or cooling stimulus to the affected area to adjust the level of pain on the skin. To better understand how people would react to the chemical stimulant, we conducted a first study to quantify the enhancement of the sensation by changing the capsaicin concentration, skin temperature, and time and to determine suitable capsaicin concentration levels. In the second study, we demonstrated that Douleur could render a variety of pain sensations in corresponding virtual reality applications. In sum, Douleur is the first wearable prototype that leverages a combination of capsaicin and Peltier to induce rich pain sensations and opens up a wide range of applications for safety education and more.