Solution-processed 2D materials on paper substrates for photodetection and photomechanical applications

Abstract

The pressing priority for flexible photo-responsive systems is scalability and simplistic fabrication routes at low production costs. The extraordinary properties seen in 2D materials, paired with solution-processing advantages, assert their employability for superior photoresponsive systems. Herein, we demonstrate versatile and flexible photodetectors and photo-thermal actuators by integrating 2D materials onto paper substrates. All-solution processed flexible photodetectors have been fabricated by spray coating dispersions of MoS₂ nanosheets onto screen printed carbon electrodes. By employing MoSe₂ as a photothermal conversion layer, actuators with paper-tape bilayers have also been demonstrated. For both photoresponsive applications, the process of calendering investigated in detail results in remarkable augmentation of the performances. Real-world thermally stimulated soft robotic applications like jacks, grippers and crawlers are realized by leveraging a configuration dependent response to illumination. Thus, a well-structured and feasible implementation of a chain of protocols that includes screen printing, spray coating, lamination and calendering with paper as the substrate led us to fabricate flexible photoresponsive systems with significantly enhanced performances.