Janus-Structured Thermal Interface Materials with Superb Vibration Adaptability for Dynamic Thermal Management

The miniaturization and integration of modern electronics along with rising power densities heighten the critical need for effective thermal management at material interfaces. Conventional thermal interface materials (TIMs) often degrade under transient thermal shock and complex mechanical vibration, rapidly diminishing interfacial thermal conductivity and compromising device reliability. Here, we report a Janus-structured TIM (J-CF/PW) consisting of an elastic and highly thermally conductive carbon foam (CF) seamlessly bonded to another one impregnated with high-entropy paraffin wax (PW), which simultaneously mitigates heat concentration and sustains thermal performance under vibration. With a low CF content of 7.7 wt %, J-CF/PW retains the high latent heat of pure paraffin while exhibiting thermal conductivity enhancements of 2363% and 15742% in the vertical and horizontal directions, respectively. Besides, it sustains excellent compressive recoverability at 30% strain even after 10,000 cycles and maintains stable thermal contact even under mechanical vibration up to 50 Hz. The asymmetric continuous architecture enables the phase-change layer to buffer transient heat flux, while the conductive carbon foam provides continuous heat-transfer pathways with inherent vibration tolerance. This design establishes a paradigm for synergistic thermomechanical optimization in dynamic thermal management applications.