Yanhu Zhang

Carbon fiber reinforced polymer (CFRP) composites pose significant challenges for precision machining due to their anisotropic structure and heterogeneous composition. This study presents a systematic ultraviolet (UV) laser processing strategy that bridges the gap between fundamental ablation mechanisms and functional bio-inspired surface engineering. Through a combination of single-pulse ablation analysis and multi-pulse scanning experiments, a processing window characterized by a 160 kHz repetition frequency and scanning speeds of 1200 to 1800 mm/s was identified, yielding high-quality grooves with minimized heat-affected zones (HAZ). A coupled thermal-mechanical finite element model was established to elucidate the differential removal behaviors of the carbon fiber and epoxy matrix. Building upon these optimized parameters, two bio-inspired micro-textures mimicking snake scales and gecko footpads were successfully fabricated. These hierarchical structures induced a transition from a semi-hydrophilic to a hydrophobic state, increasing the static water contact angle by approximately 40%. This work provides a theoretical basis for laser-material interactions in composites and demonstrates a versatile pathway for tailoring the interfacial functionality of CFRP components.

Carbon fiber reinforced polymer (CFRP) composites pose significant challenges for precision machining due to their anisotropic structure and heterogeneous composition. This study presents a systematic ultraviolet (UV) laser processing strategy that bridges the gap between fundamental ablation mechanisms and functional bio-inspired surface engineering. Through a combination of single-pulse ablation analysis and multi-pulse scanning experiments, a processing window characterized by a 160 kHz repetition frequency and scanning speeds of 1200 to 1800 mm/s was identified, yielding high-quality grooves with minimized heat-affected zones (HAZ). A coupled thermal-mechanical finite element model was established to elucidate the differential removal behaviors of the carbon fiber and epoxy matrix. Building upon these optimized parameters, two bio-inspired micro-textures mimicking snake scales and gecko footpads were successfully fabricated. These hierarchical structures induced a transition from a semi-hydrophilic to a hydrophobic state, increasing the static water contact angle by approximately 40%. This work provides a theoretical basis for laser-material interactions in composites and demonstrates a versatile pathway for tailoring the interfacial functionality of CFRP components.

The pursuit of multifunctional sensors has intensified due to their potential for integrated, efficient operation. However, realizing a flexible material that combines simplicity in the fabrication process with high performance and multifunctionality remains a formidable challenge. In this study, a multi‐interface heterostructured nanofiber membrane composed of Polyvinylidene fluoride (PVDF), HfO ₂ , and nano‐copper is fabricated, leveraging the synergistic interplay of piezoelectric and piezo‐phototronic effects for flexible, self‐powered sensing. The incorporation of hafnium oxide (HfO ₂ ) and nano‐Cu enhances the crystallinity of the piezoelectric β ‐phase and improves the dielectric properties, substantially boosting electromechanical performance. The resultant piezoelectric sensor achieves an output voltage of 15V and maintains stability over 5000 cycles at 5 Hz, enabling precise detection of human motions. Meanwhile, the PVDF/HfO ₂ ‐based photodetector exhibits broadband sensitivity (from near‐UV to near‐IR), high photoresponsivity (5.67 mA W ⁻¹ ), high detectivity (4.14×10 ¹¹ Jones), and rapid response (600 µs rising, 53 µs falling). Critically, the device demonstrates a 28.6% current enhancement under simultaneous light and pressure, highlighting a strong piezo‐phototronic effect. This work presents a multifunctional fiber film for dual‐mode sensing (pressure & light), with promising applications in wearable electronics and aerospace systems. Its straightforward fabrication and high performance offer a viable pathway toward next‐generation, flexible, self‐powered sensors.