Creating robotic intelligence using multistimuli-responsive cobalt-doped manganese oxide

Compact material constructs possessing some degree of built-in intelligence via the exhibition of complex functionalities in response to easily deliverable stimuli are highly desirable for material-powered robots. We report here a visible light-driven, dual-responsive material of cobalt-doped manganese dioxide (Co-MnO₂), which exhibits high actuation performance in terms of speed and power requirement and decreased electrical resistivity under light illumination. The actuation properties are fine-tunable by controlling the amount of Co doping, followed by an electrochemical treatment to activate the actuation, and the resistance change conveniently serves as a built-in feedback signal for controlling the actuation. Utilizing these properties, compact microrobotic devices capable of self-sensing visible light intensities of ~4 mW/cm² to perform complex motions along multiple selectable configurational pathways are fabricated. Intelligent robotic functions, including self-adapting load lifting, object sorting, and on-demand structural stiffening, are demonstrated in these devices. The concept demonstrated here opens up a perspective of creating robotic intelligence using multistimuli-responsive materials.

Runni Wu, Kin Wa Kwan, Chi Hin Mak, Alfonso Hing Wan Ngan