Ultrafast Laser Fabrication of a Flexible Sensor by Selective Ablation for a Dynamic Tactile Recognition System.

Flexible film materials are fundamental components of flexible electronics. High-precision patterning of metal on a flexible substrate is essential for device fabrication. Ultrafast laser processing offers unique advantages in precise flexible film patterning through its minimal thermal effect and high spatial resolution. However, current laser-based fabrication techniques face challenges in simultaneously controlling the ablation depth and maintaining substrate integrity. Herein, a femtosecond laser controllable ablation strategy is proposed for metal-polymer composite films that enables high-resolution patterning for tactile sensing applications. Theoretical analysis combining thermomechanical calculations and molecular dynamics simulations reveals that laser-induced stress serves as the dominant mechanism for silver layer removal. By controlling the laser fluence incident on the silver layer, selective ablation while maintaining substrate integrity is revealed. Based on the proposed strategy, high-performance flexible sensor arrays are fabricated, which are successfully integrated into a human-machine interaction system for real-time touch detection. This research advances the fundamental understanding of ultrafast laser ablation processing mechanisms and provides a reliable fabrication approach for flexible electronics and interactive systems.