Boron‑insertion‑induced lattice engineering of Rh nanocrystals toward enhanced electrocatalytic conversion of nitric oxide to ammonia

As 5G/6G electronics and aerospace modules demand lightweight yet robust components that can shield electromagnetic interference (EMI), conventional polymer-based structures fall short on temperature tolerance and mechanical strength. Now, researchers from Tsinghua University and Beihang University, led by Prof. Hui-Ming Cheng and Prof. Liqiang Zhang, have unveiled a 3D-printable graphene/Al₂O₃ ceramic framework that marries exceptional EMI shielding (> 60 dB) with compressive strength > 300 MPa—while remaining electrically and thermally tunable.

Why This Framework Matters

• EMI Shielding Excellence: 3D interconnected graphene network yields 60–90 dB attenuation (8–12 GHz), outperforming metals at 1/3 the weight.
• Mechanical Robustness: 300–400 MPa compressive strength and 30 MPa flexural strength survive 800 °C cycling—five-fold tougher than polymer composites.
• Scalable 3D Printing: Robocasting of aqueous graphene/Al₂O₃ pastes enables cm-scale lattices with 100 µm filaments; print speed up to 20 mm s^-1, ready for on-demand aerospace panels.
• Dual Functional Tailorability: Adjust graphene content (1–10 vol %) to switch from insulating (κ < 1 W mK^-1) to highly conductive (σ > 10³ S m^-1) or tune thermal conductivity for heat-spreader roles.

Innovative Design & Features

• Hierarchical Porosity: 50–300 µm macro-pores (lightweight) + sub-µm graphene wrinkles (multi-reflection) jointly dissipate EM waves while preserving ceramic stiffness.
• Rapid Sintering: Flash-spark plasma sintering at 1200 °C for 5 min suppresses graphene restacking, yielding dense Al₂O₃ necks and intact graphene pathways—energy use cut by 70 %.
• Oxidation Shield: A 50 nm Al₂O₃ skin formed in-situ encapsulates graphene, maintaining > 90 % EMI performance after 100 h at 600 °C in air.
• Multimaterial Compatibility: Framework can host SiC nanowires (microwave absorption) or BN nanosheets (thermal insulation) for mission-specific modules.

Applications & Future Outlook

• Satellite Payloads: Printed lattice inserts replace heavy Al honeycombs, saving 25 % launch mass while meeting MIL-STD-461G shielding specs.
• Hypersonic Leading Edges: Combined thermal barrier (κ ≈ 5 W mK^-1) and EMI shield survive 1600 °C surface spikes; field tests planned on C919 testbed.
• 5G Base Stations: Additively manufactured heat-sink/shield hybrids dissipate 30 % more power than Cu-heat pipes, cutting cabinet footprint by 40 %.
• Next Steps: Team is scaling to robotic DLP-stereolithography for sub-10 µm features and integrating AI-driven topology optimisation for ultra-light photonic crystal shields.

By uniting additive manufacturing with ceramic-graphene synergy, this work opens a new design space for multifunctional structures that are simultaneously strong, shielding and smart. Watch for upcoming pilot lines at Tsinghua’s Shenzhen International Graduate School and Commercial Space Shenzhen Park!