Recyclable Liquid Metal‐Based Circuit on Paper

Abstract Paper electronics is considered very environmentally friendly, but effective recyclability of metallic circuits on paper still needs more improvement. Therefore, liquid metal (Galinstan) circuits based on the reversible conversion from particles to wires are fabricated on paper using mechanical methods, i.e., mechanical sintering and sonication. Line‐width of liquid metal (LM) circuit is kept in the range of 10 µm to ≥0.5 mm by controlling the sintering force. The results demonstrate that LM circuits exhibit high electrical stability during deformation, as resistance changes only ≤4% after the passage of 10 000 folding cycles. Meanwhile, LM particles spread on paper's porous structures, have enhanced the thermal diffusivity of paper and make paper electronics work in a facile temperature when integrated with high density units. More importantly, the reborn circuits exhibit almost identical electrical stability under deformation and thermal characteristic with pristine ones, thus making LM circuits environmentally friendly during their whole life span.