Search

Flexible substrates, essential for flexible electronics by providing support and flexibility while influencing sensor stability, still face challenges in achieving mechanical and thermal stability, particularly in large-scale production and cost control. Inspired by the nacre's "brick-and-mortar" hierarchical microstructure, this study introduces PPSN (paper/polydimethylsiloxane (PDMS)/Si₃N₄ nanoparticles), a novel flexible substrate that mimics the "brick-and-mortar" structure. PPSN, with its topological interlocking and assembly technique, provides excellent thermal and mechanical stability, including high-temperature resistance and stress dissipation. An optimized Si₃N₄ content of 1.0 wt% yields a peak elastic modulus of 1245.27 MPa while maintaining hydrophobicity, with a contact angle of 127.1° at 3.0 wt%. The substrate shows excellent fatigue durability, retaining its morphology after 10,000 bending cycles. Thermal analysis indicates a stable CTE below 20 ppm/°C up to 300°C, rising to 200 ppm/°C between 350 and 400°C. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) reveal minimal thermal decomposition with mass loss below 0.5 % from 25 to 300°C and under 3 % at 400°C. Additionally, electrodes were printed on the substrate using screen printing and ion beam deposition (IBD), demonstrating good material adhesion. A flexible temperature sensor was fabricated and exhibited good sensitivity and stability with a TCR of −0.262 % °C⁻¹. PPSN advances traditional materials with superior mechanical strength, thermal stability, and durability, offering significant scientific and practical value for flexible electronics and low-cost biomimetic processes. [Display omitted] • PPSN mimics nacre's structure, offering high thermal and mechanical stability. • Peak elastic modulus at 1.0 wt% Si₃N₄, with hydrophobicity and durability. • Stable CTE below 20 ppm/°C up to 300°C with minimal thermal mass loss. • Excellent performance in flexible sensors with a TCR of −0.262 % °C⁻¹. [ABSTRACT FROM AUTHOR]