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Megan C. Coram

Publications and source records attributed to Megan C. Coram.

3 recordsLinked to original sources

Miniaturized Pneumatic Actuator Array for Multipoint Deep Pressure Tactile Stimulation

Wearable distributed tactile devices aim to provide multipoint touch stimuli, but struggle to provide sufficient forces (> 1 N) at frequencies to invoke deep pressure sensation with minimal encumbrance at small scales. This work presents a method of fabricating arrays of pneumatic actuators from thermoplastic-coated textiles. By routing pneumatic inlets to a common fold line in the fabric, we demonstrate that multiple pneumatic pouch actuators can be formed in a single simple heat-pressing operation that does not require the use of sacrificial blocking layers. The method accommodates a range of actuator diameters and spacing distances, including as compact as 8 mm diameter actuators spaced 1 mm apart, which enables use in fingertip wearable devices. In a blocked force test, these small pneumatic textile actuators exert 2.1 N when pressurized to 230 kPa. With this pair of actuators, we demonstrate an example application in which we invoke both distinct and summative stimuli, suggesting the possibility of titrating just noticeable difference in amplitude with a textile actuator array.

cs.HC

Effect of Haptic Feedback on Avoidance Behavior and Visual Exploration in Dynamic VR Pedestrian Environment

Human crowd simulation in virtual reality (VR) is a powerful tool with potential applications including emergency evacuation training and assessment of building layout. While haptic feedback in VR enhances immersive experience, its effect on walking behavior in dense and dynamic pedestrian flows is unknown. Through a user study, we investigated how haptic feedback changes user walking motion in crowded pedestrian flows in VR. The results indicate that haptic feedback changed users' collision avoidance movements, as measured by increased walking trajectory length and change in pelvis angle. The displacements of users' lateral position and pelvis angle were also increased in the instantaneous response to a collision with a non-player character (NPC), even when the NPC was inside the field of view. Haptic feedback also enhanced users' awareness and visual exploration when an NPC approached from the side and back. Furthermore, variation in walking speed was increased by the haptic feedback. These results suggested that the haptic feedback enhanced users' sensitivity to a collision in VR environment.

cs.HC

Sealing the Deal: Effects of Fabrication Parameters on the Performance of Textile Pneumatic Haptic Actuators

Textile pneumatic actuators can provide useful wearable haptic feedback when embedded in gloves, armbands, and other smart garments. Here we investigate actuators fabricated from thermoplastic coated textiles. We measure the effects of fabrication parameters on the robustness and airtightness of small, round pneumatic pouch actuators made from heat-sealed thermoplastic polyurethane-coated nylon. We determine the optimal temperature, time, and pressure for heat-pressing of the textile to create strong bonds and identify the most effective glue to create an airtight seal at the inlet. Compared to elastomeric pneumatic actuators, these textile pneumatic actuators reduce the thickness of the actuator by 96.4% and the mass by 57.2%, increasing their wearability while maintaining a strong force output. We evaluated the force output of the actuators, along with their performance over time. In a blocked force test, the maximum force transmission of the pneumatic textile actuators was 36.1N, which is 95.3% of the peak force output of an elastomeric pneumatic actuator with the same diameter and pressure. Cyclical testing showed that the textile actuators had more stable behavior over time. These results provide best practices for fabrication and indicate the feasibility of textile pneumatic actuators for future wearable applications.

cs.HC