3 ms·

Breakthrough Material Perfectly Absorbs 99% of Electromagnetic Waves

3 points by westurner 2y ago

westurner 2y ago
"Absorption-Dominant Electromagnetic Interference (EMI) Shielding across Multiple mmWave Bands Using Conductive Patterned Magnetic Composite and Double-Walled Carbon Nanotube Film" (2024) https://onlinelibrary.wiley.com/doi/10.1002/adfm.202406197 https://onlinelibrary.wiley.com/doi/10.1002/adfm.202406197 : > Abstract: The revolution of millimeter-wave (mmWave) technologies is prompting a need for absorption-dominant EMI shielding materials. While conventional shielding materials struggle in the mmWave spectrum due to their reflective nature, this study introduces a novel EMI shielding film with ultralow reflection (<0.05 dB or 1.5%), ultrahigh absorption (>70 dB or 98.5%), and superior shielding (>70 dB or 99.99999%) across triple mmWave frequency bands with a thickness of 400 µm. By integrating a magnetic composite layer (MCL), a conductive patterned grid (CPG), and a double-walled carbon nanotube film (DWCNTF), specific resonant frequencies of electromagnetic waves are transmitted into the film with minimized reflection, and trapped and dissipated between the CPG and the DWCNTF. The design factors for resonant frequencies, such as the CPG geometry and the MCL refractive index, are systematically investigated based on electromagnetic wave propagation theories. This innovative approach presents a promising solution for effective mmWave EMI shielding materials, with implications for mobile communication, radar systems, and wireless gigabit communication.
westurner 2y ago
Is this material useful for space travel and also quantum computers?
- westurner 2y ago
  It says mmWave just, though. How is it absorbing instead of reflecting energy? Do things store energy when they absorb [mmWave] EM? As phonons? Twisted Single Walled Carbon Nanotubes store energy; From "LG Chem develops material capable of suppressing thermal runaway in batteries" (2024) https://news.ycombinator.com/item?id=41745154 https://news.ycombinator.com/item?id=41745154 : > "Giant nanomechanical energy storage capacity in twisted single-walled carbon nanotube ropes" (2024) https://www.nature.com/articles/s41565-024-01645-x https://www.nature.com/articles/s41565-024-01645-x : >> 583 Wh/kg From "Gamma radiation is produced in large tropical thunderstorms" (2024) https://news.ycombinator.com/item?id=41775612 https://news.ycombinator.com/item?id=41775612 : > "Sm2O3 micron plates/B4C/HDPE composites containing high specific surface area fillers for neutron and gamma-ray complex radiation shielding" (2024) https://www.sciencedirect.com/science/article/abs/pii/S0266353824001374 https://www.sciencedirect.com/science/article/abs/pii/S02663...

3 points by westurner 2y ago

"Absorption-Dominant Electromagnetic Interference (EMI) Shielding across Multiple mmWave Bands Using Conductive Patterned Magnetic Composite and Double-Walled Carbon Nanotube Film" (2024) https://onlinelibrary.wiley.com/doi/10.1002/adfm.202406197 https://onlinelibrary.wiley.com/doi/10.1002/adfm.202406197 : > Abstract: The revolution of millimeter-wave (mmWave) technologies is prompting a need for absorption-dominant EMI shielding materials. While conventional shielding materials struggle in the mmWave spectrum due to their reflective nature, this study introduces a novel EMI shielding film with ultralow reflection (<0.05 dB or 1.5%), ultrahigh absorption (>70 dB or 98.5%), and superior shielding (>70 dB or 99.99999%) across triple mmWave frequency bands with a thickness of 400 µm. By integrating a magnetic composite layer (MCL), a conductive patterned grid (CPG), and a double-walled carbon nanotube film (DWCNTF), specific resonant frequencies of electromagnetic waves are transmitted into the film with minimized reflection, and trapped and dissipated between the CPG and the DWCNTF. The design factors for resonant frequencies, such as the CPG geometry and the MCL refractive index, are systematically investigated based on electromagnetic wave propagation theories. This innovative approach presents a promising solution for effective mmWave EMI shielding materials, with implications for mobile communication, radar systems, and wireless gigabit communication.

westurner 2y ago

Is this material useful for space travel and also quantum computers?

westurner 2y ago
It says mmWave just, though. How is it absorbing instead of reflecting energy? Do things store energy when they absorb [mmWave] EM? As phonons? Twisted Single Walled Carbon Nanotubes store energy; From "LG Chem develops material capable of suppressing thermal runaway in batteries" (2024) https://news.ycombinator.com/item?id=41745154 https://news.ycombinator.com/item?id=41745154 : > "Giant nanomechanical energy storage capacity in twisted single-walled carbon nanotube ropes" (2024) https://www.nature.com/articles/s41565-024-01645-x https://www.nature.com/articles/s41565-024-01645-x : >> 583 Wh/kg From "Gamma radiation is produced in large tropical thunderstorms" (2024) https://news.ycombinator.com/item?id=41775612 https://news.ycombinator.com/item?id=41775612 : > "Sm2O3 micron plates/B4C/HDPE composites containing high specific surface area fillers for neutron and gamma-ray complex radiation shielding" (2024) https://www.sciencedirect.com/science/article/abs/pii/S0266353824001374 https://www.sciencedirect.com/science/article/abs/pii/S02663...