▎ 摘　　要

The recently emergent laser induced graphene paper (LIGP) has endowed the large-scale assembly of 2D electronics with freestanding and multifunctional natures. Liquid sensors, a crucial component in next-generation smart devices, were developed in this report through LIGP technology. Attributed to the one-step process of computer-aided laser scribing, the new sensor was fulfilled easily with arbitrary 2D shapes, sizes and array modalities. In comparison to indirect sensing manners existed majorly in polymer binder/substrate enabled carbon devices, the novel LIGP sensors with self-supported graphitic structures evidently showed multiple superiorities, including faster response, greater reproducibility, and higher sensitivity for micro-volume liquid detections. Benefiting from the laser-process dependent structures, we further proved the tunable sensing characteristics relying dominantly on specific surface area, a critical factor for introducing capillary pressure to facilitate liquid infiltration and electrical disruption. Additionally, a dual-mode liquid-recognition strategy based on both time and speed was creatively proposed for identification of various liquids. With successful utilization of 5 x 5 LIGP array for mapping the distribution of different fluid emissions on composite structures, we highly anticipate the escalation of LIGP sensors for commercialization, roll-to-roll manufacturing, and multimodal safety-assurance applications. (C) 2019 Elsevier Ltd. All rights reserved.