Ultrathin Graphene Strain Sensor Arrays for High-Sensitivity Multifunctional Sensing with Millimeter-Scale Resolution

The deployment of graphene flexible sensor arrays is hindered by two major limitations—difficulty in achieving high spatial resolution with existing fabrication methods and the lack of system-level integration for practical applications. To address these challenges, a fully integrated platform based on an ultrathin graphene-based strain sensor array is presented. The array is fabricated on a 5 µm-thick polyimide substrate using CVD-grown graphene and top-down microfabrication techniques. With a 4 × 4 layout and 1 mm unit pitch, a device density of ≈64units cm⁻² is achieved, enabling millimeter-scale spatial resolution. The platform integrates the full development pipeline, including sensor array fabrication, flexible circuit design, signal control, and data acquisition. The durability test reveals stable performance over 5000 bending cycles. Strain sensitivity measurements show a maximum gauge factor of 144 under 0.8% strain, while dynamic tests yield rapid response and relaxation times of 0.2 and 0.16 s, respectively. The platform reliably resolves localized pressure, monitors arterial pulse waveforms, and distinguishes surface curvatures, showcasing its multifunctional sensing capabilities. These results establish the practical viability of the proposed platform for applications in wearable health monitoring, soft robotics, and next-generation flexible electronics.