A sense of ice and fire: Exploring thermal feedback with multiple thermoelectric-cooling elements on a smart ring. Issue 130 (October 2019)

• Record Type: Journal Article
• Authors: Zhu, Kening; Perrault, Simon; Chen, Taizhou; Cai, Shaoyu; Lalintha Peiris, Roshan
• Is Part Of: International journal of human-computer studies. Issue 130(2019)
• Page Start: 234
• Page End: 247
• Publication Date: 2019-10
• Subjects: Smart ring -- Thermal feedback -- Spatial thermal sensitivity -- Wearable; Human-machine systems -- Periodicals; Systems engineering -- Periodicals; Human engineering -- Periodicals; Human engineering; Human-machine systems; Systems engineering; Periodicals; Electronic journals; 004.019
• DOI: 10.1016/j.ijhcs.2019.07.003
• Languages: English
• ISSNs: 1071-5819

Abstract

Highlights: We developed three working prototypes of smart rings embedded with multiple (4, 6, and 8) thermoelectric coolers (TECs), of various sizes, which can be used with the in-ring spatial thermal patterns described in the paper. Our pilot study investigated how well users could localized the in-ring thermal feedback with three different settings. Results showed that users could reliably recognize 4 points with cold stimulation (97.2% accuracy). In the two main experiments, we investigated the use of 4 in-ring TECs to achieve two combinations of spatial thermal patterns (i.e. the neighboring or opposite patterns). The results revealed three neighboring patterns and five opposite patterns that were reliably recognized by the participants with the accuracy above 80%. The follow-up studies showed that it could be confusing for users by combining four single-spot cold stimulations, three neighboring patterns, and five opposite patterns in the same group (average accuracy: 50.2%). On the other hand, the participants could identify the thermal patterns in the combined group of the single-spot cold stimulations and the neighboring patterns (average accuracy: 85.3%), and the combined group of the single-spot cold stimulations and the opposite patterns (average accuracy: 89.3%). This suggested it could feasible to use these combined group of thermal patterns as thermal icons for information representation. We further conducted three design workshops, involving six product/interface designers. The designers suggested different mappings between the given thermal patterns and the information, including direction cueing through single-spot and neighboring patterns, artifact comparison through opposite patterns, notifying incoming calls/messages from different persons with different locations and temperatures of the TECs, etc. Abstract: In this paper, we investigate the use of thermal feedback on a smart ring with multiple thermoelectric coolers (TECs). Our prototype aims to offer an increased expressivity with spatial thermal patterns. Our pilot study showed that users could reliably recognize 4 single points with cold stimulation (97.2% accuracy). In the following two main experiments, we investigated the use of 4 in-ring TECs to achieve two categories of spatial thermal patterns by combining two neighboring or opposite elements. The results revealed three neighboring patterns and five opposite patterns that could be reliably recognized by the participants with the average accuracy above 80%. A follow-up experiment suggested that it could be confusing for users by combining four single-spot cold stimulations, three neighboring patterns, and five opposite patterns in the same group (average accuracy: 50.2%). We conducted two more follow-up studies, showing that the participants could identify the thermal patterns in the combined group of the single-spot cold stimulations and the neighboring patterns (average accuracy: 85.3%), and the combined group of the single-spot cold stimulations and the opposite patterns (average accuracy: 89.3%). We further conducted three design workshops, involving six product/interface designers, to investigate the potential applications of these thermal patterns. The designers suggested different mappings between the given thermal patterns and the information, including direction cueing through single-spot and neighboring patterns, artifact comparison through opposite patterns, notifying incoming calls/messages from different persons with different locations and temperatures of the TECs, etc. This demonstrated interest in spatial thermal patterns in smart rings not only for notifications but also for various everyday activities.