Apatura ilia‐Inspired MXene‐Based Ionic Actuator With Coupled Deformation and Optical Modulation

ABSTRACT Apatura ilia is a kind of butterfly whose wings can change color while flying. Mimicking it to design intelligent soft actuators that can simultaneously deform and modulate optical properties shows promising applications in bionic robotics, camouflage, and information security. However, the mechanism inconsistency between deformation and optical modulation hinders their integration and synchronous operation in actuators. Here, by utilizing an ion migration related mechanism, we propose a MXene‐based ionic actuator with asymmetric structures comprising an ionic polymer electrolyte, two PEDOT:PSS electrodes, and a WO 3 /MXene electrochromic layer. It exhibits reversible high‐performance deformation (displacement of 13.3 mm, 0.1–15 Hz wide frequency response) as well as synchronous optical response, including visible electrochromism and dynamic infrared emissivity modulation under 3 V voltage in air. The deformation comes from ion migration in electrodes under an electric field, while the color changing is mainly attributed to the intercalation/deintercalation of ions in WO 3 , as well as the ion enrichment by MXene. Meanwhile, based on the redox reaction on PEDOT:PSS, the actuator also realizes the dynamic modulation of infrared emissivity under voltage. This multifunctional actuator can be applied to prepare a bionic butterfly wing, achieving flapping and color‐changing, indicating prospective in robots, information encoding, and dynamic encryption systems.