Skin-Mountable Vibrotactile Stimulator Based on Laterally Multilayered Dielectric Elastomer Actuators

Skin-stimulation technology has attracted intense attention for virtual/augmented reality applications and tactile-feedback systems. However, bulky, heavy, and stiff characteristics of existing skin-stimulating devices limit their wearability and comfort, thus disturbing the immersive experience of users. This study presents a new type of thin and lightweight dielectric elastomer actuator for developing a skin-mountable vibrotactile stimulator. A new methodology is suggested to enhance the operating efficiency of dielectric elastomer actuators based on a laterally aligned dielectric multilayer structure (≈900 layer) with short dielectric distance (≈10 µm) and a soft elastomer/ionic liquid composite with low modulus and high dielectric constant. With the improved structural/material properties, the flexible actuator exhibits high displacements at low operating voltage (<200 V) over a wide frequency range (≈800 Hz). Therefore, the finger-band type vibrotactile stimulator based on the laterally multilayered dielectric elastomer actuators can exert indentations that have the ability of stimulating all mechanoreceptors in human skin over the full perception frequency/amplitude range. In addition, the actuator shows a high electromechanical stability for long-term operation due to time-efficient and precise fabrication process using sophisticated photolithography and secondary sputtering. Therefore, this vibrotactile stimulator shows high promise for use in tactile-assistive devices, tactile communications, haptic feedback, and beyond.