High-Spatiotemporal and Multimodal Soft Tactile Interface with Layered Architecture for Simultaneous Structural and Thermal Perception

Advanced robotic systems require tactile perception to interact reliably with objects in environments where visual information is limited by occlusion, illumination variations, and focusing issues. However, conventional tactile sensors are limited to single-stimulus recognition and face fundamental challenges in scalability and functionality, as miniaturizing sensor pixels reduces baseline signal levels and degrades the SNR. This study presents a high-spatiotemporal and multimodal soft tactile interface for simultaneous perception of structural and thermal profiles, fabricated through a layered architecture enabled by additive manufacturing. The proposed interface incorporates a 3D-stacked capacitive pressure sensor that combines buried interdigitated capacitors and a parallel-plate capacitor, and a reduced graphene oxide based temperature sensor within the same pixel area. The 3D-stacked electrode architecture enhances baseline capacitance within a miniaturized pixel footprint, and a via-free, interlayered interconnection scheme resolves wiring complexity in the temperature sensor array. Each sensing layer operates through independent transduction mechanisms, enabling the simultaneous perception of structural and thermal profiles with minimal cross-interference. The fabricated multimodal array can spatially resolve both contact geometry and localized thermal distributions with high-spatiotemporal resolution. Furthermore, by applying a tactile scanning strategy in robotic perception, the platform successfully identifies geometric features and surface thermal profiles of target objects even under vision-limited conditions. This study provides a scalable and robust foundation for multimodal tactile perception in advanced robotic manipulation and human-robot interaction.