Miniaturized Pneumatic Actuator Array for Multipoint Deep Pressure Tactile Stimulation

Abstract: 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.