Metal Organic Framework-MXene Nanoarchitecture for Fast Responsive and Ultra-Stable Electro-Ionic Artificial Muscles

摘要

Electro-ionic soft actuators, capable of continuous deformations replacing noncompliantrigid mechanical components, attract increasing interest in the fieldof next-generation metaverse interfaces and soft robotics. Here, a novel MXene(Ti_3C_2T_x) electrode anchoring manganese-based 1,3,5-benzenetricarboxylatemetal-organic framework (MnBTC) for ultrastable electro-ionic artificial musclesis reported. By a facile supramolecular self-assembly, the Ti_3C_2T_x-MnBTChybrid nanoarchitecture forms coordinate bond, hydrogen bond, and hydrophilicinteraction with the conducting polymer of poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS), resulting in a mechanically flexible andelectro-ionically active electrode. The superior electrical and electrochemicalperformances of the electrode stem from the synergistic effects betweenintrinsically hierarchical nanoarchitecture of MnBTC and rapid electron transportbehavior of Mxene, leading to fast diffusion and accommodation of ionsin the ion-exchangeable membrane. The developed artificial muscle based onTi_3C_2T_x-MnBTC is found to exhibit high bending displacement (12.5 mm) andultrafast response time (0.77 s) under a low driving voltage (0.5 V), along withwide frequency response (0.1–10 Hz) and exceptional stability (98 retentionat 43,200 s) without any distortion of actuation performance. Furthermore, thedesigned electro-active artificial muscle is successfully used to demonstratemimicry of eye motions including eyelid blinking and eyeball movement in a doll.