Quantized Channels and Instability Modulation Strategy in Au/PDMS Single-Crack Evolution.

Controllable conductive channels in crack-based sensors are crucial for stable microdeformation detection, yet the random formation of disordered crack networks in conventional sensors hinders the precise analysis of single-crack contributions to sensing performance. We propose a stress-engineered single-crack architecture in Au/PDMS films, achieving control over conductive channel evolution through three distinct regimes: (I) nonpenetrating crack initiation, (II) metal point contact, and (III) fully penetrated fracture. High-resolution in situ monitoring reveals strain-quantized conductance in regime II, demonstrating ballistic transport with reproducible quantum steps (2e2/h multiples). While Regime III exhibits poor instability from stochastic conductive pathways, strategic integration of single-walled carbon nanotubes crack-bridging networks fundamentally transforms the conduction mechanism, stable resistance changes (ΔR/R0 ≈ 106) at 2.45% strain. The coupled quantum-classical conduction mechanisms and hybrid nanoengineering strategy establishes new principles for ultrasensitive, stable epidermal electronics and AI-enhanced biomedical diagnostics.