SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4028-5
The escalating thermal management demands of modern electronics necessitate materials with superior thermal conductivity and matched thermal expansion. Cu/Diamond composites are promising, yet their fabrication typically requires extreme conditions (high temperature/pressure) or complex coating processes. This work introduces a one-step, heat-source-free cold manufacturing method using ultrasonic vibration to consolidate Cu/Diamond composites at room temperature and a low pressure of ~16 MPa within seconds. The applied pressure is reduced by 200–500 times, and the required temperature is only 20% of that used in conventional high-temperature high-pressure sintering. Direct metallurgical bonding at Cu-Cu interfaces and solid embedding of diamond particles in the Cu matrix are achieved, yielding a composite with a high yield strength of 150 MPa. The method enables a maximum diamond proportion of ~60%, resulting in a thermal conductivity exceeding 1043 W/(m·K) and a coefficient of thermal expansion below 10×10⁻⁶ K⁻¹. Complex shapes are readily fabricated, and heat dissipation tests demonstrate superior performance compared to commercial Al₂O₃ and AlN substrates. The loose preparation conditions and rapid processing confer significant industrial production potential.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4043-3
In-plane InAs nanowires and nanowire networks are promising platforms for electronics, optoelectronics, and topological quantum computing due to their small electron effective mass, narrow bandgap, high electron mobility, strong spin-orbit coupling, and large Landé g factor. However, their selective area growth on CMOS-compatible group-IV substrates remains challenging. Here, we report the selective area growth of high-quality in-plane InAs nanowires and nanowire networks on Ge(111) substrates by molecular-beam epitaxy. Conventional selective-area epitaxy fails to simultaneously achieve good selectivity and continuity. To overcome this, we developed a metal-sown, single-indium-source two-step growth method, which attains both selectivity and continuity but yields nanowires with rough surfaces and lengths below 10 μm. We then introduced an upgraded metal-sown, dual-indium-source two-step growth method, successfully fabricating in-plane InAs nanowires and nanowire networks with smooth surface morphology and lengths exceeding 60 μm. By optimizing the As beam equivalent pressure, overgrowth at network junctions is effectively suppressed, resulting in uniform nanowire networks. High-resolution transmission electron microscopy and Raman spectroscopy confirm the high-quality single-crystalline nature and pure zinc-blende structure of the nanowires and networks. This work establishes a foundation for fabricating high-quality in-plane InAs/superconductor hybrid nanowires and nanowire networks on Ge substrates.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4007-x
Hydrogels, with their hydrophilicity, flexibility, and environmental friendliness, are highly desirable for moisture-electric generators (MEGs) that harness ubiquitous moisture to generate electrical energy. As the active material layer in MEGs, hydrogels play a crucial role in absorbing atmospheric moisture and converting chemical potential energy into electricity. However, the relatively low output current of the device and the instability of hydrogels pose challenges to the development of high-performance hydrogel-based MEGs. Herein, we introduce a straightforward, feasible, cost-effective, and versatile two-step solvent displacement strategy to overcome the barrier associated with the development of MEGs. Through tunable solvent interactions of glycerol and water, the moisture absorption capability and stability of the hydrogel can be improved, while promoting favorable ion migration. Such an effective processing route not only significantly boosts the output performances but also greatly improves the long-term durability of hydrogel-based MEGs. Notably, the current output and power density of the treated MEGs can increase by up to two orders of magnitude. The mechanisms behind the intriguing observation are investigated by various characterizations and theoretical calculations. This universal strategy holds promise to be extended to various hydrogel-based MEGs. Moreover, the MEGs can be used for energy harvesting, self-powered respiratory monitoring, and non-contact humidity detection. This work offers new opportunities for advancing green energy and self-powered technologies.