A cross-scale honeycomb architecture-based flexible piezoresistive sensor for multiscale pressure perception and fine-grained identification

Trade-off between sensitivity and the pressure sensing range remains a great challenge for flexible pressure sensors. Micro-nano surface structure-based sensors usually show high sensitivity only in a limited pressure regime, while porous structure-based sensors possess a broad pressure-response range with sensitivity being sacrificed. Here, we report a design strategy based on a cross-scale architecture consisting of a microscale tip and macroscale base, which provides continuous deformation ability over a broad pressure regime (10⁻⁴-10⁴ kPa). The cross-scale honeycomb architecture (CHA)-based piezoresistive sensor exhibits an excellent sensitivity over a wide pressure range (0.5 Pa-0.56 kPa: S₁ ∼ 27.97 kPa⁻¹; 0.56-20.40 kPa: S₂ ∼ 2.30 kPa⁻¹; 20.40-460 kPa: S₃ ∼ 0.13 kPa⁻¹). As a result, the CHA-based sensor shows multiscale pressure perception and fine-grained identification ability from 0.5 Pa to 40 MPa. Additionally, the cross-scale architecture will be a general structure to design other types of sensors for highly sensitive pressure perception in a wide pressure range and its unit size from microscale to macroscale is beneficial for large-scale preparation, compared with micro-nano surface structures or internal pores.