Skin-integrated stretchable actuators toward skin-compatible haptic feedback and closed-loop human-machine interactions

Skin-integrated haptic interfaces that can relay rich information from machines to humans are desirable, yet existing devices struggle to produce skin-compatible haptic cues. This work presents stretchable soft electrostatic actuators with pressure-amplification structures that match the skin’s perception range, spatial resolution, and stretchability. A scalable self-assembly process fabricates pressure-amplification pillars, yielding output pressures beyond skin perception thresholds without increasing voltage. Miniaturized device dimensions enable actuator arrays with 3 mm pitch, suitable for skin sites with the highest spatial acuity. A haptic feedback system combining these actuators with highly sensitive porous pressure sensors is demonstrated. Two proof-of-concept applications show transmission of surface texture and object shape information sensed at the robot side to the user, enabling closed-loop human–machine interaction.