Ion-Electron Fusion Transparent Film for Interactive Soft Robotics

Marine organisms combine sensory networks and bioluminescence to achieve adaptive interaction in complex environments. Existing bioinspired soft robots, however, mainly focus on actuation and rarely integrate both functionalities to enhance autonomy. Flexible transparent conductive films offer a promising route for strain-based proprioception and visible light communication, but maintaining stable conductivity and high transparency under large deformations remains challenging. Here, An ion-electron fusion film is presented, termed i-PEDOT:PSS, comprising a poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) layer on an ionic substrate. The interfacial ion penetration, in combination with the pre-formed microcrack structure, imparts i-PEDOT:PSS with robust conductivity and desirable strain-sensing capability under large strain. The i-PEDOT:PSS achieves a highly linear and repeatable electromechanical response over strains up to 300%, approximately three times that of previously reported transparent strain sensors, while maintaining an optical transmittance of 93%. Benefiting from these properties, i-PEDOT:PSS serves as a multifunctional component in soft robotic systems. As a strain sensor, it enables real-time monitoring and adjustment of the locomotion state of underwater transparent soft robots. As a stretchable transparent electrode, it supports electroluminescent devices for underwater optical signal transmission. This work established a fully soft, interactive robotic platform, offering a new framework for the development of perceptive and communicative soft robotics.