A Patterned Graphene/ZnO UV Sensor Driven by Integrated Asymmetric Micro-Supercapacitors on a Liquid Metal Patterned Foldable Paper

A foldable array of patterned graphene/ZnO nanoparticle UV sensor and asymmetric micro-supercapacitors (AMSCs) integrated on a paper substrate with patterned liquid metal interconnections is reported. The resistor type UV sensor based on graphene/ZnO nanoparticles is patterned to be driven by the stored energy of the integrated AMSCs. The AMSC consists of MnO₂ nanoball deposited multiwalled carbon nanotubes (MWNTs) and V₂O₅ wrapped MWNTs as positive and negative electrodes, respectively. As an electrolyte, propylene carbonate-poly(methyl methacrylate)-LiClO₄, an organic solvent-based gel, is used. The UV sensor and AMSCs can be easily integrated on a liquid metal, Galinstan, patterned, waterproof mineral paper and show a mechanically stable UV sensing, regardless of repetitive folding cycles. This work demonstrates a novel foldable nanomaterial based sensor system driven by integrated energy storage devices, applicable to future wearable and portable electronics.