Tag Archives: North Korea

I am a sound speaker/loudspeaker (well, maybe one day)

Caption: From left are Saewon Kang, Professor Hyunhyub Ko, and Seungse Cho in the School of Energy and Chemical Engineering at UNIST. Credit: UNIST

What are these scientists so happy about? A September 18, 2018 news item on ScienceDaily reveals all,

An international team of researchers, affiliated with UNIST [Ulsan National Institute of Science and Technology] has presented an innovative wearable technology that will turn your skin into a loudspeaker.

An August 6, 2018 UNIST press release (also on EurekAlert but published September 17,2018), which originated the news item, delves further into the research,

This breakthrough has been led by Professor Hyunhyub Ko in the School of Energy and Chemical Engineering at UNIST. Created in part to help the hearing and speech impaired, the new technology can be further explored for various potential applications, such as wearable IoT sensors and conformal health care devices.

In the study, the research team has developed ultrathin, transparent, and conductive hybrid nanomembranes with nanoscale thickness, consisting of an orthogonal silver nanowire array embedded in a polymer matrix. They, then, demonstrated their nanomembrane by making it into a loudspeaker that can be attached to almost anything to produce sounds. The researchers also introduced a similar device, acting as a microphone, which can be connected to smartphones and computers to unlock voice-activated security systems.

Nanomembranes (NMs) are molcularly thin seperation layers with nanoscale thickness. Polymer NMs have attracted considerable attention owing to their outstanding advantages, such as extreme flexibility, ultralight weight, and excellent adhesibility in that they can be attached directly to almost any surface. However, they tear easily and exhibit no electrical conductivity.

The research team has solved such issues by embedding a silver nanowire network within a polymer-based nanomembrane. This has enabled the demonstration of skin-attachable and imperceptible loudspeaker and microphone.

“Our ultrathin, transparent, and conductive hybrid NMs facilitate conformal contact with curvilinear and dynamic surfaces without any cracking or rupture,” says  Saewon Kang in the doctroral program of Energy and Chemical Engineering at UNIST, the first author of the study.

He adds, “These layers are capable of detecting sounds and vocal vibrations produced by the triboelectric voltage signals corresponding to sounds, which could be further explored for various potential applications, such as sound input/output devices.”

Using the hybrid NMs, the research team fabricated skin-attachable NM loudspeakers and microphones, which would be unobtrusive in appearance because of their excellent transparency and conformal contact capability. These wearable speakers and microphones are paper-thin, yet still capable of conducting sound signals.

“The biggest breakthrough of our research is the development of ultrathin, transparent, and conductive hybrid nanomembranes with nanoscale thickness, less than 100 nanometers,” says Professor Ko. “These outstanding optical, electrical, and mechanical properties of nanomembranes enable the demonstration of skin-attachable and imperceptible loudspeaker and microphone.”The skin-attachable NM loudspeakers work by emitting thermoacoustic sound by the temperature-induced oscillation of the surrounding air. The periodic Joule heating that occurs when an electric current passes through a conductor and produces heat leads to these temperature oscillations. It has attracted considerable attention for being a stretchable, transparent, and skin-attachable loudspeaker.

Wearable microphones are sensors, attached to a speaker’s neck to even sense the vibration of the vocal folds. This sensor operates by converting the frictional force generated by the oscillation of the transparent conductive nanofiber into electric energy. For the operation of the microphone, the hybrid nanomembrane is inserted between elastic films with tiny patterns to precisely detect the sound and the vibration of the vocal cords based on a triboelectric voltage that results from the contact with the elastic films.

“For the commercial applications, the mechanical durability of nanomebranes and the performance of loudspeaker and microphone should be improved further,” says Professor Ko.

Thankfully, the researchers have made video that lets us hear this sound speaker,


Paper-thin stick-on speakers, developed by Professor Hyunhyub Ko and his research team at UNIST.

Thank you to the folks at UNIST for including something with the sound. Strangely, it’s not common practice to include audio when publishing research on sound, not in my experience anyway..

Here’s a link to and a citation for the paper,

Transparent and conductive nanomembranes with orthogonal silver nanowire arrays for skin-attachable loudspeakers and microphones by Saewon Kang, Seungse Cho, Ravi Shanker, Hochan Lee, Jonghwa Park, Doo-Seung Um, Youngoh Lee, and Hyunhyub Ko. Science Advances 03 Aug 2018: Vol. 4, no. 8, eaas8772 DOI: 10.1126/sciadv.aas8772

This paper appears to be open access.

North Korea’s nanotechnology

I don’t usually rewrite material from elsewhere (sometimes called churnalism) but since these people (Global Post, North Korea Newsletter No. 275, Aug. 15, 2013) seem very concerned about any kind of copying whatsoever and I’m determined to mention North Korea’s nanotechnology efforts on this blog for the first time., here goes.

Apparently North Korea has established a nano center as of April 2013 which was officially announced on Aug. 1, 2013 by Rodong Sinmun newspaper of the Workers’ Party of (North) Korea (WPK). They claim advances in energy, environmental conservation, medicine, farming, and light industry.

Yonhap News has an Aug. 2, 2013 news item which provides some detail,

The newspaper [WPK] monitored in Seoul said the nanotech center, built under the guidance of North Korean leader Kim Jong-un, has played a key part in developing the sector. It added that roughly 1,000 nano products and prototypes were on display at the 10th nano science exhibition that opened on Tuesday [July 30, 2013].

North Korean media started mentioning the nanotech center in April, although no detail was made public on when it was established.

It said the country’s technicians from universities and laboratories have been able to develop agricultural sterilizers, growth accelerators, air cleaners and shoes.

The Korean Central News Agency (KCNA) on Aug. 7, 2013 claimed that due to previous efforts there are now hundreds of  nanotechnology researchers and specialists.

London’s Poetry Parnassus helps set the stage for 2012 Olympics

The world’s largest poetry event is over. The Poetry Parnassus, organized as part of London’s 2012 Cultural Olympiad celebrating the Olympics, took place from June 26 – July 1, 2012. (I first wrote about it in my April 20, 2012 posting when they were asking for more poet nominations as the organizers wanted to have a poet from each nation represented at the Olympics as part of the Poetry Parnassus.)

By all accounts this was as extraordinary gathering. Alice Gribbin in her July 3, 2012 article for the New Statesman provides some context for along with some details about the actual event,

Poetry Parnassus, the “back of an envelope” idea of Simon Armitage, artist-in-residence of the Southbank Centre, saw 204 poets from as many countries come together to represent their nation’s poetic tradition at the many-venued culture complex on the Thames. Readings and workshops, parties and debates filled six days and nights.

Did you know Somalia is possibly the world’s most poetry-loving nation? Such takeaways about the global poetry scene were easy to come by over the week, but far more interesting was the demonstration of how many various ways people of countries around the world relate to poems. Take Somalia again: while poetic expression there is the base from which almost all other creative outlets develop – and most people can recite many poems – the tradition is entirely aural.

At dusk over Jubilee Gardens, behind the London Eye, a helicopter dropped 100,000 cards printed with poems by 300 contemporary poets. The “aeronautical display” by Chilean collective Casagrande had adults and children jumping for poetry, or merely gazing at the “Rain of Poems” that gently fell against the city skyline. Later, crossing Waterloo Bridge, I read the first I had caught …

I have a very short video clip featuring the “Rain of Poems”,

As for anyone who might find the notion of a poetry event as part of the Olympic Games somewhat odd, Tony Perrottet in a June 29, 2012 article for The New York Times Sunday Book Review discusses the London Poetry Parnassus and poetry’s history as part of the original Olympics,

… the relationship between poetry and the Olympics goes back to the very origins of the Games. In ancient Greece, literary events were an indispensable part of athletic festivals, where fully clothed writers could be as popular with the crowd as the buff athletes who strutted about in the nude, gleaming with olive oil. Spectators packing the sanctuary of Zeus sought perfection in both body and mind. Champion athletes commissioned great poets like Pindar to compose their victory odes, which were sung at lavish banquets by choruses of boys. (The refined cultural ambience could put contemporary opening ceremonies, with their parade of pop stars, to shame.) Philosophers and historians introduced cutting-edge work, while lesser-known poets set up stalls or orated from soapboxes.

Criticism could be meted out brutally: when the Sicilian dictator Dionysius presented subpar poems in 384 B.C., disgusted sports fans beat him up and trashed his tent. At other Greek athletic festivals, like those at Delphi, dedicated to Apollo, the god of poetry and music, verse recital was featured as a competitive event, along with contests for the lyre and choral dancing.

For much of the 20th century, poetry was an official, medal-winning competition in the Games. …

According to Perrottet’s article, 1948 was the last year that poetry was a medal event at the modern Olympics.

The July 1, 2012 article by Sylvia Hui for the Huffington Post offers another perspective on the recent event,

He says he was one of late North Korean leader Kim Jong Il’s favorite propaganda artists, singing the praises of the Dear Leader in dozens of poems. But these days Jang Jin-sung says he prefers to tell the truth about North Korea.

“North Korea has nuclear programs, but South Korea has the media,” said Jang, who is in London for a global poetry festival involving poets from countries competing in the July 27 to Aug. 12 London Olympics. “Truth is the strongest weapon.”

Jang’s poems now tell of public executions, hunger and desperate lives. He said that the piece he chose to submit to London’s Poetry Parnassus festival, “I Sell My Daughter for 100 Won,” is based on one of his worst memories in North Korea – recollections of a mother trying to sell her daughter in the market place.

For anyone who might like to read Jang’s poem or any of the others that were part of the Poetry Parnassus, the UK”s Guardian newspaper has an interactive map here.