Zhongshan Deng

Traditional polymethyl methacrylate (PMMA) bone cement faces challenges, including stress shielding due to its high elastic modulus and thermal damage from polymerization exotherm. This study develops a novel BiInSn-PMMA composite bone cement that simultaneously addresses these limitations. The results demonstrate that the mechanical properties of the composite bone cement can be effectively controlled by adjusting the ratio of BiInSn powder, thus meeting the requirements of different bone tissues. The phase change characteristics of BiInSn significantly reduce thermal risk, lowering the peak temperature in surrounding tissues from 57.6 °C to 48.3 °C and shortening the duration above 47 °C from 210 s to 39 s. In addition, the introduction of BiInSn provides the composite bone cement with good radiographic visibility while exhibiting excellent cytocompatibility in vitro . Overall, this BiInSn-PMMA composite bone cement possesses adjustable mechanical properties, low risk of thermal damage, good radiographic visibility, and low cytotoxicity, demonstrating its potential value in bone defect repair.

Spontaneous growth of a CuGa ₂ intermetallic layer acts as an “electronic bridge” at the liquid metal–copper interface. This reactive wetting mechanism facilitates stable metallic bonding and achieves stable contact resistance.

Chronic pain imposes substantial burdens on both individuals and society. For patients who have not responded to conservative treatments, spinal cord electrical stimulation (SCS) may be used as a therapeutic option. However, existing SCSs rely on rigid power delivery systems that can cause inflammation, limiting their long‐term stability and usability. In this study, an implanted flexible wireless electrical stimulator (WES) based on liquid metal (LM) high‐density coils is proposed, which can be applied to chronic pain treatment. The LM coil is fabricated using soft lithography and reversible bonding techniques, providing a higher effective number of turns and greater flexibility than existing coils, while maintaining mechanical stability to withstand over 1000 bending cycles. Furthermore, the WES system provided precisely tunable output voltages (±0–2 V), enabling tailored stimulation protocols. In a rodent model of neuropathic pain, WES therapy elicited a remarkable 60% improvement in weight‐bearing capacity, and the expression of pain‐sensitive factors is significantly reduced after treatment. The inductive electromotive force remained stable after implantation, and the tissue at the implantation site is in favorable condition. This work demonstrates the efficacy of LM high‐density coils for chronic pain management through in vivo implantation experiments, thereby laying the foundation for future long‐term, implantable, and wirelessly powered medical devices.

Liquid metal phase change materials have the advantages of high thermal conductivity and high volumetric latent heat, which are expected to address the growing challenges of thermal management of advanced electronics. In previous studies, the effect of radiative heat transfer from fins of a phase change heat sink on thermal management performance has rarely been considered. In this study, radiative coating materials with high emissivity were prepared and coated on the fins of the liquid metal phase change heat sink. The effect of radiative heat transfer on the performance of liquid metal phase change heat sink was investigated. The experimental results of continuous heating under natural convection conditions show that the introduction of the radiative coating with an emissivity of 0.9298 can extend the time for the surface temperature of the heat source to reach 100 °C by 9.4%, while shortening the recovery time of the phase change heat sink by 14.9%. The results of high-power cyclic heating indicate that the high emissivity coating can reduce the peak temperature by 16.6 °C in the tenth working cycle. A simplified numerical model was subsequently developed and validated to determine the specific effects of phase change and radiative heat transfer on the overall thermal control performance. The radiation-enhanced liquid metal phase change heat sink proposed in this study is simple and maintenance-free. It is expected to address the thermal management issues of electronic devices that cannot use active cooling or operate in thin-air environments.