New Tech: US flag could act as a speaker to play the National Anthem

This is curious new technology; imagine the US Flag being able to play the National Anthem from the flagpole!

How scientists turned a flag into a loudspeaker


EAST LANSING, Mich. – A paper-thin, flexible device created at Michigan State University not only can generate energy from human motion, it can act as a loudspeaker and microphone as well, nanotechnology researchers report in the May 16 edition of Nature Communications.

The audio breakthrough could eventually lead to such consumer products as a foldable loudspeaker, a voice-activated security patch for computers and even a talking newspaper.

“Every technology starts with a breakthrough and this is a breakthrough for this particular technology,” said Nelson Sepulveda, MSU associate professor of electrical and computer engineering and primary investigator of the federally funded project.

“This is the first transducer that is ultrathin, flexible, scalable and bidirectional, meaning it can convert mechanical energy to electrical energy and electrical energy to mechanical energy.”

In late 2016, Sepulveda and his team successfully demonstrated their sheet-like device – known as a ferroelectret nanogenerator, or FENG – by using it to power a keyboard, LED lights and an LCD touch-screen. That process worked with a finger swipe or a light pressing motion to activate the devices – converting mechanical energy to electrical energy.

Like a traditional loudspeaker, this sheet-like, flexible device can transmit sound. Created by MSU engineers, the device — known as a ferroelectret nanogenerator, or FENG — can be embedded into a flag or other fabric. It could one day lead to a foldable loudspeaker or an audio newspaper. CREDIT Michigan State University

The current breakthrough extends the FENG’s usability. The researchers discovered the high-tech material can act as a microphone (by capturing the vibrations from sound, or mechanical energy, and converting it to electrical energy) as well as a loudspeaker (by operating the opposite way: converting electrical energy to mechanical energy).

To demonstrate the microphone effect, the researchers developed a FENG security patch that uses voice recognition to access a computer. The patch was successful in protecting an individual’s computer from outside users. “The device is so sensitive to the vibrations that it catches the frequency components of your voice,” Sepulveda said.

To demonstrate the loudspeaker effect, the FENG fabric was embedded into an MSU Spartan flag. Music was piped from an iPad through an amplifier and into the flag, which then reproduced the sound flawlessly. “The flag itself became the loudspeaker,” Sepulveda said. “So we could use it in the future by taking traditional speakers, which are big, bulky and use a lot of power, and replacing them with this very flexible, thin, small device.”

Imagine a day when someone could pull a lightweight loudspeaker out of their pocket, slap it against the wall and transmit their speech to a roomful of people, Sepulveda said.

“Or imagine a newspaper,” he added, “where the sheets are microphones and loudspeakers. You could essentially have a voice-activated newspaper that talks back to you.”

Wei Li, an MSU engineering researcher and lead author of the paper in Nature Communications, said other potential applications of the FENG include noise-cancelling sheeting and a health-monitoring wristband that is voice-protected.

“Many people are focusing on the sight and touch aspects of flexible electronics,” Li said, “but we’re also focusing on the speaking and listening aspects of the technology.”

The innovative process of creating the FENG starts with a silicone wafer, which is then fabricated with several layers, or thin sheets, of environmentally friendly substances including silver, polyimide and polypropylene ferroelectret. Ions are added so that each layer in the device contains charged particles. Electrical energy is created when the device is compressed by human motion, or mechanical energy.


The paper:

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May 16, 2017 9:43 am

My Tips & Notes post yesterday on nanotech battery:
Chimp May 15, 2017 at 5:25 pm
Word to the wise. Graphene. ‘Nuff said:
“Holey” not a typo.

Ron Williams
Reply to  Chimp
May 16, 2017 10:04 am

Chimp, Have you heard of this pure natural Coated Spherical Purified Graphite play in Alabama? Seems to have great promise in a friendly jurisdiction with support from AG Jeff Sessions. While this is proving up to be a potentially great deposit for existing L-ION batteries, I assume the jump to nano graphene is the next step.
Alabama Graphite Corp. OTCQB: CSPGF

Reply to  Ron Williams
May 16, 2017 10:08 am

No, I haven’t. Thanks.
An Army buddy of mine with relatives in AL does a funny standup routine on land-use planning in AL, contrasting it with socialist OR, using actual instances. His relations wanted to sell fried chicken out of their garage, so they just cut a hole in the wall and did so. Their neighbor wanted to open up a junk yard in his back yard, and just did it.

Ron Williams
May 16, 2017 9:50 am

Siri, please play the national anthem. Don’t you just love technology? This is why ultimately you have to be an optimist for the long term future, albeit politics is probably the fly in the ointment. There will be some bumps in the road, but I think human kind does well for the long term future.

Reply to  Ron Williams
May 16, 2017 11:10 am

But the bad guys eventually get the technology and do vast amounts of damage with relatively little effort. I’m less optimistic.

Ron Williams
Reply to  Gary
May 16, 2017 12:21 pm

It is definitely better now than it has been throughout much of recorded history, but that depends where you are locally. Overall, our lot is much better off than even our grandparents time when life expectancy was 65, and much less than 100 years previous that. Humanity has a long history of conflict and bad guys, but we always triumph over that in the end. Maybe thanks to the long time British Commonwealth/USA system of governance/check on abuse of power and protected freedoms. I think we get a handle on the bad guys, because if we don’t, then we don’t do so well and at some point we will have to deal with all these bad guys or live in a dystopian future. Oldest story in the book I know, but it will take time. My bet is on the resilience of humanity over the long term.
What keeps me up at night is global cooling since after all, we are just one little rock orbiting the Sun in near absolute zero all around us for light years. The geological record is full of such cooling events that bring literal death and destruction to the planet overnight. If it is bad enough that we miss a crop in the northern hemisphere, then that will be a severe challenge for humanity and not everyone will survive. The odds this happens is probably a lot higher than runaway global warming, which is probably an impossibility just due to the physics involved. But cooling is just a heartbeat away with any major chaotic event so we should be planning on identifying and mitigating real problems, and not whether CO2 is our most urgent problem in the world to solve. That is the intellectual evil that the ‘bad guys’ are peddling today.

Reply to  Gary
May 17, 2017 6:32 am

G, imagine Google, Oracle, FB, NSA… scattering this as confetti and gathering up every sound, using vibration and wind to power cameras to gather up video. If anyone can abuse it, they will.
RW, In my grandparents’ time average life expectancy was around 40…and had been for centuries.

May 16, 2017 9:53 am

Interesting tech. Let’s see what actually happens with this.

Bryan A
Reply to  Tom Halla
May 16, 2017 10:00 am

Once they get yhe voice aspect worked out, the Video Angle is just around the corner. Imagine a patch on your poclet that records/transmits video images around you directly to storage/transmission sources.
Radio and Television weren’t that far apart technologically speaking

Reply to  Bryan A
May 16, 2017 11:45 am

But it took years .
The transformation which astounds me in its suddenness was the transition for silent to talkies from 1929 to 1930 .
I define old media as not having a blog mechanism .

Rhoda R
Reply to  Tom Halla
May 16, 2017 10:58 am

But they’d really get ahead by inventing a process that allows the consumers to talk to the newspapers, not the other way around.

Reply to  Rhoda R
May 16, 2017 11:02 am

Most newspapers and other news outlets just want affirmation, not debate. Consider what they routinely do with comments on their stories.

May 16, 2017 10:03 am


J Mac
Reply to  Astrosmith
May 16, 2017 12:05 pm


Eustace Cranch
May 16, 2017 10:36 am

which then reproduced the sound flawlessly.
“Flawlessly” is a highly subjective term. While I don’t doubt the technology works, I’m pretty sure it’s not exactly flat from 20Hz to 20kHz. I’d be very surprised if it can reproduce much below a few hundred Hertz.

D. J. Hawkins
Reply to  Eustace Cranch
May 16, 2017 11:08 am

Can you elucidate? What is there about thin-film speakers that might keep them from reproducing sound below, say, 400 Hz?

Eustace Cranch
Reply to  D. J. Hawkins
May 16, 2017 11:30 am

To reproduce low frequencies, you have to move a LOT of air. That’s why woofers are bigger than tweeters, and typically have large cone excursion. The range of motion for thin-film speakers is TINY. They physically can’t move a lot of air unless they’re the size of a wall. Also for small diaphragms you have the problem of the out-of-phase back wave cancelling out the front at low frequencies.
Almost all planar film-type high fidelity speakers are either huge or have a cone subwoofer for bass. Sometimes both.

Reply to  D. J. Hawkins
May 16, 2017 3:31 pm

I agree with Eustace. The other technology that is a large flat sheet is electrostatic speakers. My buddy had those back in the 70s. They had pretty crappy low end response.
Good bass response requires a lot of air movement. link That means the speaker cone has to be big and it has to move a long distance.
As a wild-ass-guess, I would say that planar (flat sheet) speakers move back and forth about a tenth of a millimetre. To displace a litre of air, the area would have to be 100,000 cm^2. That’s ten square metres.

Reply to  D. J. Hawkins
May 16, 2017 9:29 pm

yah, the magnaplanars were cool but need separate base
wavelength, you know
speed of sound is @ 1,125 ft/s, so a 20kHz wave is only 0.675 inches distance peak to peak while a 20 Hz wave is 56.25 feet long
reproduction of audio wavelengths suffers proportionately to the diaphragm’s travel limit.

Reply to  D. J. Hawkins
May 16, 2017 11:00 pm

Eustace is entirely correct. Now add the fact that a flag (or a newspaper of even a tablet) hasn’t the mass to prevent the speaker’s motor from simply modulating it instead, thus having no audible effect at a relatively high frequency. Anything input into the device below that point simply vanishes.
The best speakers in the world are made from hundreds of pounds of inert materials not just because they’re expensive furniture, but because you must quieten the mechanical environment the active elements – the transducers – are housed in and push against. A speaker has to do actual physical work, some of it energizing a good deal of air in wavelengths dozens of feet long while at the same time not moving at all at frequencies measured in fractions of inches. Any spurious movement or resonant sympathy simply becomes its own acoustical source, creating audible distortion.

Leo Smith
Reply to  D. J. Hawkins
May 17, 2017 1:24 am

Might be handy for LCD panels to give them sound capability, tweet-wise any way.
You would need conventional woofers.

J Mac
Reply to  Eustace Cranch
May 16, 2017 12:07 pm

Was thinking similarly…

Alan Watt, Climate Denialist Level 7
May 16, 2017 10:55 am

Does this mean we can generate useful energy from all the noise at “March for Science” events? Wow, talk about a renewable resource!

May 16, 2017 11:14 am

No mention of the cost, of course……Me thinks too many people have too much time on their hands. Let me know when it does something useful…

Reply to  Butch
May 16, 2017 11:14 am

AND cost effective…

May 16, 2017 11:39 am

I think there’s a lot of hype in this .
See and :
Here’s the most teky image in the YouTube :
As I would have expected , the sound from the flag is very tinny — lacks lows .
Given the very short “throw” of the surface , I don’t see how it could generate long wavelengths . Maybe someone can enlighten me .
This line in the release really made me wonder about the competence of the whole project .but may reflect more the competence of the release writer .
“The device is so sensitive to the vibrations that it catches the frequency components of your voice,” Sepulveda said.
Huh ?
It then sounds like it does a frequency analysis within itself rather than simply being a reasonably flat microphone over the vocal range .

Paul Penrose
Reply to  Bob Armstrong
May 16, 2017 3:15 pm

I expect this to be more revolutionary in the sensor area initially. Used to replace a push buttons and other touch/motion sensors, especially in battery powered devices where it could potentially boost battery life. But it is a bit scary to think that something which looks like a piece of cloth could be a microphone.

Reply to  Bob Armstrong
May 16, 2017 10:49 pm

There have been at least a few alternative, flat-film attempts at speakers over the years. They generally sound poorly, with narrow bandwidths and peaky responses. (The “flawless” sound in this article is to be taken very, very loosely. I think they mean “the thing audibly worked” more than it obsoleted the loudspeaker industry. Somebody’s always obsoleting the speaker business…)
Recreating a reasonable sonic facsimile is no small thing. The problem is that creating acoustical power takes a relatively big scale transduction of electrical energy with acceptably low distortion across a very wide band. The state of the art? It’s still large multi-way horn systems, meaning multiple enormous physical horns and sophisticated driving electronics and filters. It takes a very great deal of coordination to actually move air in enough quantity with low enough distortion to sound right.
Unlike the video display, I’d doubt that the next magic speaker comes from a flat format pretty much forever. The physics aren’t even close to similar, and their formidability can’t be cheated.

May 16, 2017 1:35 pm

But it is better than anything I knew about (bum boatie, sure, but I try to read WUWT and some news) – say, last week.
The first telephone was restricted – but now we have Samson Sevens and Eye-Phone Eights [or similar – haven’t fact-checked or device-checked (or spell checked: they don’t look quite right) with son].
Now we have newspapers that – potentially, noting comment at Tom Halla May 16, 2017 at 11:02 am [Above] – could listen!
Maybe the BBC ? ? – ahhhhhhh – no!
Too far-fetched even for 2017 . . . . .

May 16, 2017 1:55 pm

Hmmm. As it works both ways, perhaps as a hidden microphone? Speak directly into my shirt…

May 16, 2017 2:38 pm

I can here it now! A quartet of toilet seat covers 🙂

The Badger
May 16, 2017 3:04 pm

I seem to remember “Wireless World” did a DIY project on a flat plastic film loudspeaker in , I think, the 1970’s. They also mentioned the reverse use as a microphone.

chris y
Reply to  The Badger
May 16, 2017 6:21 pm

Polyvinylidene fluoride (PVDF) was first demonstrated as a piezoelectric polymer in 1969 by Dr. Heiji Kawai. It can be used as a speaker and a microphone. It can be used to generate electricity.
After scanning through the Nature paper, I was unable to locate any quantitative measurements of the electro-mechanical coupling coefficient k of this new material, to be able to compare it with PVDF and other piezoelectric and ferroelectric materials.

Reply to  chris y
May 18, 2017 2:14 pm

Years ago, I read an article about the military putting piezo’s in the souls of the soldiers boots to charge up their electrical devises as they marched along.

May 16, 2017 6:41 pm

Turning a flag into a loudspeaker – what problem is this solving? The fact that they’ve chosen such a pointless gimmick to promote the technology suggests that the technology doesn’t have a real-world application.
And before you say “but the laser had no use when it was invented”, think of the thousands of inventions since the laser that have turned out to have no use. Go into a hi-fi store and ask to buy a quadraphonic sound system (that should be good for a laugh, if nothing else).

May 16, 2017 7:46 pm

The guy at the laserdisc store used to have a quadrophonic sound system. There is a niche collector’s market for old technologies. Not sure he made any money at the store, but he did drive a Porsche, so maybe he didn’t need to.

Leo Smith
May 17, 2017 1:21 am

…then reproduced the sound flawlessly….

Mein Gott! I haf spent $50,000 on loudspeakers for nuthink!

Bill Thomson
May 17, 2017 4:50 am

In order to make sound you have to push air, and in order to do that you have to have something to push against. It’s that old “every action has an equal and opposite reaction” stuff. A flag just doesn’t cut it, no way, no how.

May 17, 2017 8:42 am

The paper at Nature has no mention of the word “flawlessly”, or even the string “flaw”.
It seems that only the press release claims “reproduced the sound flawlessly.”
A reminder: University and NASA press releases are hype. The bigger (or more self-important) the university, the bigger the hype.

May 17, 2017 9:38 am

It’s all mysterious to me. Microphone and loudspeaker adjacent or touching, or even the same thing! When I use mikes and speakers I need to avoid feedback very carefully, especially when the speakers generate much more power than the mikes absorb, and this is the whole point of an amplifier. There must be a simple explanation I suppose, but one does not occur to me.
Frankly, I believe nothing of it as yet.

Reply to  robinedwards36
May 17, 2017 9:55 am

A conventional moving coil loudspeaker works as a decent microphone too. Alexander Graham Bell used one in his original telephone before Thomas Edison managed to displace it with his carbon microphone invention. He tried to replace the earpiece too, but as history showed, moving coil speakers had a lot of life in them.
So, you can use the material as a speaker or a microphone. You might be able to filter out a tiny signal from the microphone effect, but that’s probably only of interest to surveillance situations where you can’t kill the music or put a microphone in the centerpiece on the table.

Reply to  Ric Werme
May 17, 2017 1:11 pm

I wonder how I got that impression, I was probably around 10 at the time. I might have decided that if it wasn’t a carbon mike, it must have been the only other possibility I knew of then. (I didn’t know about condenser/electret mikes then.) has more info.
I also didn’t know about Emile Berliner’s and others work on carbon microphones.

Michael Fabing
May 17, 2017 3:46 pm

You mean that my toilet paper could talk to me as I unroll it? Will there be ads for personal hygiene products? Food? Politics? Dating sites?

May 18, 2017 12:06 pm

As an audiophile since the 1960s, who has built many DIY speakers and subwoofers since the 1960s, I believe this article is nearly complete BS.
There have been “flat” speakers since the 1960s, so that’s not new.
The problem with flat speakers is the first three to four octaves of bass from the rear of the driver is out of phase with the first three to four octaves of bass from the front of the driver = cancellation = weak bass = low fidelity non-full range sound — maybe okay if you only listen to violin quartets and don’t need any bass!

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