Self-adaptive capacitive-resistive mode-conversion sensor for thermo-tactile perception via high-κ nanocomposites

Abstract

The thermo-tactile linkage perception of human skin is an important mechanism for maintaining life safety. However, existed biomimicking electronic skin sensors are difficult to achieve active regulation of touch by temperature information. So far, some multimodal and multifunctional flexible sensors have made progress, but most of them are limited to independent signal acquisition and parallel processing, lacking the cross-modal collaborative response capability of biological organisms. Therefore, this work proposes a self-adaptive capacitive-resistive mode-conversion pressure sensor, whose mode-converting function can be achieved by a high relative permittivity (high-κ) nanocomposite layer and a temperature sensitive insulation layer. The capacitive pressure sensing mode is constructed at the ambient temperatures below the phase transition temperature of the insulation layer, exhibiting high stability and repeatability. When the ambient temperature rises to the phase transition point, conductive pathways are formed, thus the flexible pressure sensor converts to resistive pressure sensing mode. The mode conversion characteristics were experimentally demonstrated through robot hand grasping the hot water cup, where temperature-triggered adaptive converting of sensing mechanism. This mode-conversion flexible pressure sensor achieves perception of dangerous temperatures through the recognition of electrical signal patterns, providing new ideas for the development of intelligent electronic skin with environmental adaptability.