Laser-Induced Surface Reconstruction of Carbon Fiber Cloth with Enhanced Capillary Performance for Flexible Thermal Management

To address the issues of poor flexibility, insufficient capillary performance, and weak bending fatigue resistance of traditional wicks in thermal management of flexible electronic devices, this paper proposes the surface modification of carbon fiber cloth (CFC) using 1064 nm laser to prepare a wick with both high capillary performance and flexibility. By adjusting laser power and scanning spacing, the influence rules on CFC’s surface morphology, chemical composition, wettability, and capillary performance were systematically explored, and its reliability was verified through bending cycle experiments. The results show that laser processing constructs micronano convex structures on the CFC surface and introduces oxygen-containing functional groups via the thermal oxidation effect, realizing a controllable transition from superhydrophobicity (contact angle 150.1°) to superhydrophilicity (contact angle 0°). When the laser power is 24 W and the scanning spacing is 0.1 mm, the capillary rise height reaches 150 mm, the capillary factor is 18.30 mm/s 0.5, and the average rise rate is 3.91 mm/s. After 2000 bending cycles, the loss of capillary height and capillary factor is no more than 7%; even after 8000 bending cycles, more than 50% of the comprehensive capillary performance is retained, which is much better than that of traditional metal wicks. Compared with existing wicks, the laser-modified CFC wick achieves the synergistic optimization of “flexible adaptation” and “high-performance capillary transport”, providing a solution for efficient thermal management of flexible electronic devices and also offering theoretical support for surface modification and performance optimization of flexible heat-dissipating materials.