▎ 摘　　要

A surface acoustic wave (SAW) formaldehyde sensor based on a graphene/polymethyl methacrylate (PMMA) composite film with high sensitivity, and short response and recovery time was proposed in this study. Using a novel multi-source spray deposition method, graphene sheets were uniformly dispersed in a PMMA film to fabricate sensitive films with a three-dimensional framework structure for use in SAW devices. The formaldehyde-sensing ability was enhanced by optimizing the film thickness and operating temperature. The highest performance was achieved for a graphene/PPMA film thickness of 2.2 mu m at a temperature of 120 degrees C.