Self-sensing Soft Tactile Actuator for Fingertip Interface

In this paper, we report a self-sensing soft tactile actuator based on Dielectric elastomer actuator (DEA) for wearable haptic interface. DEAs are one of electroactive polymer actuators, which are reported to have large area strain and fast response speed. A soft tactile actuator is constructed of a multi-layered DEA membrane layer, a passive membrane layer, and an inner circular pillar. The soft actuator was optimized by varying the geometry, and the force and displacement tests were conducted under a frequency range of 0 to 30 Hz. The selected actuator produces an output force up to 0.9 N, with a displacement of 1.43 mm. To provide accurate physical force feedback to the user, the actuator is integrated with a 1.1 mm thick film-type soft force sensor that enables feedback control. Under the pressure, touch layer contacts with the core, and the light inside the core scatters to the touch layer. A fabricated soft force sensor can measure the force in a range of 0 to 1.25 N under various frequency ranges. Our wearable prototype exhibits high output force of 0.9 N, as well as flexibility, conformity, and light-weight structure (3.2 g).