Transparent rubber 'ionic' speaker paves the way for 'soft machines'

New invention demonstrates the possibilities of ionic conductors, allowing for stretchable, see-through electronics.

Researchers from the University of Harvard have demonstrated an ‘ionic’ speaker made from a thin sheet of rubber.

In a video released by the university (see above) the transparent disc was hooked up to a laptop and used to play the ‘Morning’ prelude from Peer Gynt.

The speaker demonstrates the possibilities of using ‘ionic’ conductors, an alternative to regular electronics in which the electrical charge is carried by ions rather than electrons.

Ions are relatively large and heavy compared to electrons, and ionic systems are typically difficult to work with. This new proof of concept promises that ionic conductors might have practical applications after all.

These conductors offer several advantages when compared to standard electronics: they can be stretched to many times their normal are without increasing resistivity (a problem for regular stretchable electronics); they can be entirely transparent; and the gels they are constructed from are biocompatible, meaning they would be easy to incorporate into biological systems.

“The big vision is soft machines,” says co-lead author Christoph Keplinger, who worked on the project as a postdoctoral fellow at Harvard SEAS and in the Department of Chemistry and Chemical Biology. “Engineered ionic systems can achieve a lot of functions that our body has: they can sense, they can conduct a signal, and they can actuate movement. We’re really approaching the type of soft machine that biology has to offer.”

As Jeong-Yun Sun and Christoph Keplinger demonstrate here, two major advantages of ionic conductors are that they can be very stretchy and completely transparent, two properties difficult to achieve with electronics.

“We’d like to change people’s attitudes about where ionics can be used,” says Keplinger. “Our system doesn’t need a lot of power, and you can integrate it anywhere you would need a soft, transparent layer that deforms in response to electrical stimuli—for example, on the screen of a TV, laptop, or smartphone to generate sound or provide localized haptic feedback—and people are even thinking about smart windows. You could potentially place this speaker on a window and achieve active noise cancellation, with complete silence inside.”

The finished speaker used a high-voltage signal to vibrate the rubber, creating sounds that spanned the entire audible spectrum – from 20 hertz to 20 kilohertz.

For more details on the work, see the official press release from Harvard University.

To make the speaker, a membrane of transparent, insulating rubber is sandwiched between two layers of transparent, conductive gel. The electrical connection to the power source is established outside of the active region of the device, where it does not need to be transparent.

News
peopleHowards' Way actress, and former mistress of Jeffrey Archer, was 60
Sport
Romelu Lukaku puts pen to paper
sport
News
Robyn Lawley
people
Arts and Entertainment
Unhappy days: Resistance spy turned Nobel prize winner Samuel Beckett
books
PROMOTED VIDEO
News
people
Life and Style
Troy Baker and Ashley Johnson voice the show’s heroes
gamingOnce stilted and melodramatic, Hollywood is giving acting in video games a makeover
News
i100
Life and Style
Phones will be able to monitor your health, from blood pressure to heart rate, and even book a doctor’s appointment for you
techCould our smartphones soon be diagnosing diseases via Health Kit and Google Fit?
News
people
Extras
indybest
Travel
Ryan taming: the Celtic Tiger carrier has been trying to improve its image
travelRyanair has turned on the 'charm offensive' but can we learn to love the cut-price carrier again?
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Sport
Usain Bolt confirms he will run in both the heats and the finals of the men's relay at the Commonwealth Games
commonwealth games
Life and Style
Slim pickings: Spanx premium denim collection
fashionBillionaire founder of Spanx launches range of jeans that offers 'thigh-trimming construction'
News
Sabina Altynbekova has said she wants to be famous for playing volleyball, not her looks
people
News
i100
Life and Style
tech'World's first man-made leaves' could use photosynthesis to help astronauts breathe
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

SAP Project Manager

competitive: Progressive Recruitment: SAP PROJECT MANAGER - 3 MONTHS - BERKSHI...

SAP Project Manager

competitive: Progressive Recruitment: SAP PROJECT MANAGER - 3 MONTHS - BERKSHI...

Senior Investment Accounting Change Manager

£600 - £700 per day + competitive: Orgtel: Senior Investment Accounting Change...

Microsoft Dynamics AX Functional Consultant

£65000 - £75000 per annum + benefits: Progressive Recruitment: A rare opportun...

Day In a Page

Save the tiger: The day America’s love of backyard tigers led to a horrific bloodbath

The day America’s love of backyard tigers led to a horrific bloodbath

With only six per cent of the US population of these amazing big cats held in zoos, the Zanesville incident in 2011 was inevitable
Samuel Beckett's biographer reveals secrets of the writer's time as a French Resistance spy

How Samuel Beckett became a French Resistance spy

As this year's Samuel Beckett festival opens in Enniskillen, James Knowlson, recalls how the Irish writer risked his life for liberty and narrowly escaped capture by the Gestapo
We will remember them: relatives still honour those who fought in the Great War

We will remember them

Relatives still honour those who fought in the Great War
Star Wars Episode VII is being shot on film - and now Kodak is launching a last-ditch bid to keep celluloid alive

Kodak's last-ditch bid to keep celluloid alive

Director J J Abrams and a few digital refuseniks shoot movies on film. Simon Usborne wonders what the fuss is about
Once stilted and melodramatic, Hollywood is giving acting in video games a makeover

Acting in video games gets a makeover

David Crookes meets two of the genre's most popular voices
Could our smartphones soon be diagnosing diseases via Health Kit and Google Fit?

Could smartphones soon be diagnosing diseases?

Health Kit and Google Fit have been described as "the beginning of a health revolution"
Ryanair has turned on the 'charm offensive' but can we learn to love the cut-price carrier again?

Can we learn to love Ryanair again?

Four recent travellers give their verdicts on the carrier's improved customer service
Billionaire founder of Spanx launches range of jeans that offers

Spanx launches range of jeans

The jeans come in two styles, multiple cuts and three washes and will go on sale in the UK in October
10 best over-ear headphones

Aural pleasure: 10 best over-ear headphones

Listen to your favourite tracks with this selection, offering everything from lambskin earmuffs to stainless steel
Commonwealth Games 2014: David Millar ready to serve up gold for his beloved Scotland in the end

Commonwealth Games

David Millar ready to serve up gold for his beloved Scotland in the end
UCI Mountain Bike World Cup 2014: Downhill all the way to the top for the Atherton siblings

UCI Mountain Bike World Cup

Downhill all the way to the top for the Atherton siblings
Save the tiger: The animals bred for bones on China’s tiger farms

The animals bred for bones on China’s tiger farms

The big cats kept in captivity to perform for paying audiences and then, when dead, their bodies used to fortify wine
A former custard factory, a Midlands bog and a Leeds cemetery all included in top 50 hidden spots in the UK

A former custard factory, a Midlands bog and a Leeds cemetery

Introducing the top 50 hidden spots in Britain
Ebola epidemic: Plagued by fear

Ebola epidemic: Plagued by fear

How a disease that has claimed fewer than 2,000 victims in its history has earned a place in the darkest corner of the public's imagination
Chris Pratt: From 'Parks and Recreation' to 'Guardians of the Galaxy'

From 'Parks and Recreation' to 'Guardians of the Galaxy'

He was homeless in Hawaii when he got his big break. Now the comic actor Chris Pratt is Hollywood's new favourite action star