Abstract: This paper presents the design and fabrication of a pressure sensor based on reduced graphene oxide suspended film (rGO-SF). The rGO-SF was formed through in-situ growth on pre-etched SiO₂ cavities, where self-assembled graphene oxide (GO) films spontaneously separated from solution. Compared with conventional graphene-based pressure sensor fabrication processes, the rGO-SF sensor eliminates membrane transfer steps, significantly simplifying the manufacturing workflow and providing advantages for large-scale production. By introducing modified polymethyl methacrylate (M-PMMA) into the rGO interlayers, the oxygen transmission rate (OTR) of the M-PMMA/rGO composite film was reduced by 49.6% (at 20.0wt% M-PMMA loading), markedly enhancing the stability and reliability of the rGO-SF pressure sensor. Experimental results demonstrate that pressure differences between internal and external environments induce measurable resistance changes in rGO-SF. Leveraging this principle, precise pressure measurement can be achieved by monitoring resistance variations. Testing shows the sensor effectively detects pressure changes in the 0 kPa to 100 kPa range, with excellent linearity (S²=0.99) and sensitivity (1.298×10^-3 kPa^-1) particularly in the 30 kPa to 100 kPa differential pressure regime.

Key words: pressure sensors, reduced graphene oxide, suspended films, self-assembly, composites