Intrinsic Force-Temperature Self-Decoupling Enables Human-like Tactile Sensing in a Soft Ionic Skin

Soft dual-modal tactile sensors capable of simultaneously sensing force and temperature are essential for enhancing human-like perception and interaction in robots, particularly in the functional sense of concurrent mechanical and thermal perception. However, achieving self-decoupled and high-fidelity dual-modal sensing remains a significant challenge due to intrinsic signal crosstalk, structural complexity, and limited flexibility in existing designs. Here, we present a soft robotic tactile (RoboTac) skin that intrinsically decouples force and temperature using an ionic conductive film within a minimalist architecture, featuring an ultralight weight and an ultralow cost. Ionic conductivity enables independent readouts without algorithmic compensation by allowing thickness compression to modulate capacitance (force) and lateral ionic transport under thermal stimuli to modulate resistance (temperature). Moreover, the RoboTac skin demonstrates its practical utility for robots in object perception, specialized tasks, and human-robot interaction. This work establishes a general principle for intrinsically self-decoupling modalities in tactile sensors, advancing multimodal sensing, intelligent perception, and embodied robotics.