# Affective Stroking: Design Thermal Mid-Air Tactile for Assisting People in Stress Regulation
## 4 Discussion
### Design Implications  
4.2.1. Individual Haptic Sensory Experiences Vary Significantly and User's Needs Differ  
Numerous studies have highlighted that touch heavily relies on individualized contextual interpretation. Individual customization to meet specific needs is essential.  
* The touch of the skin with different intensities affects the tactile sensation: Because we used mid-air tactile to imitate touch on human skin, most users appreciated the gentle sensation it provided. However, some users felt that the intensity was still insufficient compared to physical touch, lacking a sense of realism. Some participants mentioned that touch is not always at the same intensity. Further design should consider the change in stroking intensity to imitate real touch sensations. Others reported a tingling sensation akin to electric shock. This might be due to the fact that we connected eight fan devices simultaneously, and the MCU's supply voltage and current were insufficient, leading to inadequate power for each individual device. As a result, the airflow was weaker or produced a tingling sensation. Variations in hardware fan specifications might also cause inconsistencies in start-up times during operation, affecting continuity and diminishing the realism of the touch experience. Future designs should find appropriate voltage and current supply, consider the balance between airflow intensity and speed, and test the different sensory experiences they provide to users.
* People like thermal tactile at different individuals' preferences: To simulate human body temperature, we maintained the temperature at 32 \(\pm\) 0.5 \({}^{\circ}\)C. Most users stated that a warm touch makes them feel real. They found this range comfortable and acceptable, while a few expressed contrary opinions, feeling either too hot or too cold. Previous studies have indicated a wide variability in users' temperature perceptions; some users experience pleasure from warmth [62,68], while others find cold temperatures pleasurable [68,69]. Future designs should further explore how variations in temperature intensity and rate affect sensory experiences. Consideration could be given to allowing users to customize the temperature to better suit their individual needs.
* Variations in stroking rhythm provide more real touch sensations: During the relaxation phase, we provided users with a fixed, uniform stroking rhythm, which led some users to perceive it as monotonous, particularly over the course of 5 min. Future designs should incorporate variations in stroking rhythm to enhance user experience. This could include one-directional repetitive stroking, bi-directional back-and-forth stroking, or variations in rhythm and pauses during stroking, all of which could contribute to a more authentic stroking sensation. Additionally, offering users the ability to customize their stroking preferences could be considered.
* Considering different body parts and areas for relaxation: Many users felt that applying the touch solely on the forearm was insufficient. They expressed a desire for this tactile experience to extend to more body parts, such as the head and face, and even for a full-body relaxation experience. Our mediated stroking simulation has evoked a sense of relaxation in users reminiscent of various other contexts. These similar experiences have led users to desire that our technology also provide comparable sensations in similar body areas.