The focus of this project was the research and development of an affective social touch wearable. AffectiveAir uses pneumatic actuation on the shoulder to convey a library of haptic sensations. The goal was to overcome physical limitations in potential digital communication contexts, by a non-verbal, tactile, and possibly intimate social touch using pneumatic actuation. This would offer a way for individuals to connect, much like in face-to-face interactions

The embodiment of the prototype is the result of an iterative design process based on literature research, benchmarks, and user tests. The wearable actuator, designed to be worn on the back of the shoulder, is secured using an elastic band that attaches to the wearer’s pants. A custom-designed, thin polyurethane airbag with an integrated nozzle provides a soft, textile-integrated actuator solution. An external pneumatic control system controls the airflow, allowing for inflation under 1000- and deflation under 100 milliseconds. Effects of the actuator are monitored using an air pressure sensor and force sensitive resistor, offering controlled feedback and data logs for prototyping and user research.

Multiple user tests functioned as a means to explore and verify new designs throughout the project. Initial tests identified the shoulder as an effective and acceptable location for the feedback, and an airbag of 40x40mm was determined to provide the best balance between intensity and comfort for this specific location. Subsequent tests determined optimal pressure levels for pneumatic haptics on the shoulder and evaluated user responses to various pneumatic patterns.

Results revealed that it was challenging for participants to distinguish pressure levels from each other within the 0 to 500 mbar range. However, there were promising results in the general identification of increasing or decreasing pneumatic patterns using three pressure levels of 75, 200 and 500 mbar. ‘TripleShort’ received the highest identification rating at 85%, while ‘short staircase down’ received the lowest rating at 44%.

Patterns with a prolonged high pressure level at the end such as ‘heartbeat forward’ and ‘long staircase up’ received a slighly higher comfort and pleasantness rating compared to others, where the latter was rated the least exciting at lower speed. Overall ratings remained close to the median across tests with variable speed or pressure levels.

General user feedback on the prototype and haptic experience was positive, with participants noting the novelty and the sensation’s occasional resemblance to intimate human touch. Feedback from the interview also notes how context and social relationship status closely relates to the acceptability of receiving such feedback. The ergonomics of the prototype were considered satisfactory, allowing for adjustment to fit any body size and position the feedback on the back of the participant’s shoulder.

In conclusion, AffectiveAir demonstrated the potential for affective touch through a pneumatic shoulder wearable. It offers a library of identifiable and characterized pneumatic patterns and the ability to extend the possible actuations with adjustable parameters. The project’s outcomes suggest promising potential for further research using affective pneumatic haptics, applicable not only in mediated communication but also in other possible areas such as gaming and navigation.