Want to see through walls? Electroboffins build tiny chip in the lab that vibrates at just the right frequency to do it
- Reference: 1585289165
- News link: https://www.theregister.co.uk/2020/03/27/wall_vibration_chip/
- Source link:
Terahertz radiation lies in the electromagnetic spectrum where microwaves and infrared meet. These so-called T-waves, ranging from 0.3 to 3THz according to the ITU, have interesting properties: they can travel through clothing, wood, walls, and even human skin, for one thing.
However, they can be tricky to produce, depending on the application, as you often need expensive and clunky equipment. Now, a team of researchers led by the ?cole polytechnique f?d?rale de Lausanne (EPFL) in Switzerland believe they?ve created something that not only emits high-power terahertz radiation but is both compact and cheap. Which is useful for miniaturization and productization.
The gizmo detailed in a paper [1]published in Nature this week works by producing so-called nanoplasma.
Here?s how it works: two tiny metal plates are placed 20 nanometres apart and a voltage is applied. Electrons migrate towards one of the plates to create a nanoplasma. When enough negative charge has accumulated and the voltage across the plates reaches a critical threshold, the electrons instantly flock to the other plate.
Just in case you were expecting 10Gbps, Wi-Fi 6 hits 700Mbps in real-world download tests [2]READ MORE
?The very high electric field in the small volume of the nanoplasma leads to ultrafast electron transfer, resulting in extremely short time responses,? the paper explained. This back and forth motion of the electrons on each plate continues, and the device emits a high-intensity pulse of terahertz waves.
?We achieved an ultrafast switching speed, higher than 10 volts per picosecond (10 -12 s), which is about two orders of magnitude larger than that of field-effect transistors and more than ten times faster than that of conventional electronic switches,? the academics said.
The tiny nanoplasma devices were fabricated on bits of Kapton tape pasted onto a sapphire substrate, where a thin layer of gold or tungsten was stacked on top of titanium.
?High-frequency semiconductor devices are nanoscale in size,? [3]said Elison Matioli, co-author of the study and an electrical engineering professor at EPFL.
?They can only cope with a few volts before breaking out. High-power devices, meanwhile, are too big and slow to generate terahertz waves. Our solution was to revisit the old field of plasma with state-of-the-art nanoscale fabrication techniques to propose a new device to get around those constraints.?
?High-frequency, high-power and nanoscale aren?t terms you?d normally hear in the same sentence,? he added.
The fast switching speeds could help deliver ultrafast chips that could be used in wireless communication, sensors, or even biomedical imaging. ?
[1] https://www.nature.com/articles/s41586-020-2118-y
[2] https://www.theregister.co.uk/2019/12/05/wifi6_700mbps_speeds/
[3] https://actu.epfl.ch/news/a-nanoscale-device-that-can-see-through-walls/
Ugh!
"productization"
Dear God, would not "production" have been the better word to use?
Now I know that the US and Britain are "two nations divided by a common language" but use of portmanteau words like this should really be a criminal offence.
Re: "productization"
Indeed, "productization" is an inexcusably hideous construction. But I think it is intended to mean "implemented and put to use in a product" or "turned from this into a saleable product", or this like, so not quite the same as a bare "production", which does not necessarily have the same implications.
Still, several words to cover the intended meaning would have been better than the single jargonoid one used here.
Re: "productization"
There you go!
Re: "jargonoid"
I do not like this ugly, negative, "jargonoid" neologism of yours. I suggest the more elegant and positive "jargolicious" instead :-)
Re: "jargonoid"
It would appear that jargolicious is derived from the words jargon and delicious, whereas, if the intention is to show something that is derived soley from the word jargon it should be jargonicious.
"productization"
I think the author was looking for a word that means making a product of this capability.
Admittedly, a phrase should have been chosen.
At last - the X-ray specs
from the back of mad magazine are in my future!
Re: At last - the X-ray specs
A sad young fellow named Jones
Sat and grumbled and griped and then moaned
For he bought x-ray specses
To look through girls' dresses
And all he could see was their bones...
Re: At last - the X-ray specs
Aye, and they refused to give me a refund!
Kapton tape, sapphire substrate, gold or tungsten and titanium
I don't know what they're going to make, but I'm sure it won't come cheap.
Re: Kapton tape, sapphire substrate, gold or tungsten and titanium
everything brand new will be expensive. as this technique expands, a million possible uses will emerge. lasers were very slow to be adopted for real-world use but now they're everywhere.
Aren't you glad that the police (and many others) will now be able to spy on you through the walls of your house?
Though this would also be extremely useful if you can run WiFi over it. Vastly higher data rate, and no problem with walls blocking the signal.
The exterior walls of many homes contain foil-backed fiberglass insulation. Perhaps the metal foil will shield the home somewhat? (Many low-E windows also contain a membrane which may attenuate certain wavelengths?) It would be interesting to hear some legitimate test results about this.
Oooh the hype!
Let me first clarify the science behind this story:
The researchers take an ordinary, boring high-frequency source (they show data using a 10 MHz source) and send it through their "switch". Each time the "boring source" output exceeds a threshold voltage, their switch turns on very fast, leading to a sharp (picosecond) voltage rise at the output. When the boring source output goes low, the switch output falls again -- although slowly.
When you take that fast rising pulse and send it through a suitable circuit, you can get some very short pulse corresponding to the derivative of the pulse rise. So they can get a very short THz frequency pulse (picosecond duration). Then they have to wait for their boring source to go low and go up to the threshold voltage again before they can get another pulse (100 ns wait time for the 10 MHz boring source).
The great "power" of the source (power = energy / time) is, of course, calculated for the picosecond duration. But when you account for the long wait between the pulses, you'll notice that the average power is not impressive. It's a nanoscale device, so don't get overexcited!
The yadayada on the Great Power of Microwaves is factually correct, but falls into the category of the famous exam answer: "The questions about worms is interesting, because worms have similar shape and mobility to elephant trunks and I can tell you all about elephants ..." Concerning wireless communication, I don't see how a fast switch with very long reset time will help. Maybe some more magic to come...
Kapton tape is wonderful stuff
And it's a good job it's sticky, too, because these tiny things are going to be a devil of a job to solder!