The lightest electromagnetic shielding material in the world

[➕👇 ꓤꓱꓷꓠꓵ🎵Tone]

If you have dealt with interference in either audio or data transmission (or if you had a VW Beetle and you just couldn't get rid of the static in the radio), this may interest you...

 

"Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic components or the transmission of signals. High-frequency electromagnetic fields can only be shielded with conductive shells that are closed on all sides. Often thin metal sheets or metallized foils are used for this purpose. However, for many applications such a shield is too heavy or too poorly adaptable to the given geometry. The ideal solution would be a light, flexible and durable material with extremely high shielding effectiveness.

 

"The lightest electromagnetic shielding material in the world"

 

Read on to see how they do it...

https://phys.org/news/2020-07-lightest-electromagnetic-shielding-material-world.amp

 

 

Old (Downunder) Tone

 

 

 

 

 

Edited July 4, 2020 by Maʹher-shalʹal-hash-baz
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[Qapla]

Not what you would expect for this type of shielding

 

Quote

The researchers have succeeded in producing a composite of cellulose nanofibers and silver nanowires, and thereby created ultra-light fine structures which provide excellent shielding against electromagnetic radiation. The effect of the material is impressive: with a density of only 1.7 milligrams per cubic centimeter, the silver-reinforced cellulose aerogel achieves more than 40 dB shielding in the frequency range of high-resolution radar radiation (8 to 12 GHz) - in other words: Virtually all radiation in this frequency range is intercepted by the material.

 

[➕👇 ꓤꓱꓷꓠꓵ🎵Tone]

This bit fascinated me:

"To create pores of optimum size and shape, the researchers pour the material into pre-cooled molds and allow it to freeze out slowly. The growth of the ice crystals creates the optimum pore structure for damping the fields.

With this production method, the damping effect can even be specified in different spatial directions: If the material freezes out in the mold from bottom to top, the electromagnetic damping effect is weaker in the vertical direction. In the horizontal direction—i.e. perpendicular to the freezing direction—the damping effect is optimized."

I wonder how they discover this aspect... 'Oh, let's freeze it from left to right and see what happens...'?

Old (Downunder) Tone

[Qapla]

Back in the 1970's I knew a Brother who was involved in research and development of cable TV boxes. At the time they were developing a box that had better ability to decode premium channels and track signal usage. They used a digital address for the box that could be read from the cable suppliers. The idea was that the information they could detect allowed the provider to determine if a TV subscriber was watching channels they were not paying for by monitoring the exact frequencies that were going out the cable that went to the TV. This was very high-tech at the time.

 

Once designed these boxes were built on the assembly line on printed circuits. The ones they built in this shop were all hand made on project circuit boards. In doing so, they made some resistance coils that were simply wire wound in a "spring like" configuration. They discovered that the orientation of the coil to the circuit board made a difference. If it was perpendicular to the circuit board it worked differently then it did when parallel to the board. They would make several boards all the same and then install the coils at various angles to see what the effect was and use the design best suited to their end goal.

 

I guess the point I am making is that, while most of us might not think of something like this, those who design and invent them do - thus why and how the team making the shielding material would try these things

 

1 hour ago, Maʹher-shalʹal-hash-baz said:

I wonder how they discover this aspect... 'Oh, let's freeze it from left to right and see what happens...'?

 

Yes, that is exactly what they do ... it is all part of the process.