Scientists have designed a “skin” that senses when concrete structures are damaged

Image: Bittbox via Flickr, reproduced under creative commons.

Concrete is pretty great, isn’t it? It’s strong, it’s cheap, it’s easy to use. Let’s hear it for concrete!

On the downside, though, it’s also prone to cracking – if there are swift changes in temperature, for example, or if it’s bearing too much weight. Cracks in concrete structure are annoying at the best of times, but if said structure is holding, say, nuclear waste, they can also be disastrous.

So a team of scientists from North Carolina State University and the University of Eastern Finland have developed plans for a “skin” that would flag up cracks or damage to the concrete’s surface. Their idea involves installing electrodes at the edges of a structure, then applying electrically conductive copper paint across the concrete. The electrodes would emit a constant, low-level current across the surface of the painted “skin”, monitored by a computer. If the surface was weakened, cracked or damaged, the paint would become less conductive, and the computer would sense a change in the signal. You can even analyse the data to produce a map of the damage.

Here’s a cracked piece of concrete, alongside a computer rendering of the damage:

Image: Aku Seppänen.

So far, the researchers have only tried the method out on small, 1m long pieces of concrete, but they’re hoping to test on bigger areas. Dr Mohammad Pour Ghaz, one of the paper’s co-authors, said the team were keen to show the method could work on “real-world structures”.

 
 
 
 

Is Berlin ready to be Europe's tech capital?

The Berliner Dome, lit up for 2014's Festival of Light. Image: Getty.

“Berlin should be the capital of sextech!” MakeLoveNotPorn founder Cindy Gallop booms from the main stage at Tech Open Air, before trailing off with the half-hearted: “Because, well, nowhere else is.” A lukewarm call to arms for a city which prides itself on, amongst other things, sex appeal.

But Berlin – riding the crest of the wave in music, art, nightlife, and effortless cool – has seemed from the outside to nonchalantly paddle in the shallows in terms of mainstream acceptance of tech. It’s not just that Uber is limited to professional metered taxis or that Airbnb has been banned from renting out full apartments: paying by credit or debit card is still looked on as an unholy art in bars, cafes and many supermarkets.

Even at TOA, billed as “Europe’s leading interdisciplinary technology festival”, attendees unarmed with wads of cold, hard cash wee left shivering and caffeine-deprived in the decidedly non-open-air weather on 14 July. If only Bitcoins could keep you warm.

But despite rendering half your usual apps and your Mastercard near useless, Berlin’s otherwise welcoming atmosphere is attracting waves of international interest and a burgeoning start-up scene pushing it to the forefront of development in Europe.

“Berlin will never be Silicon Valley, ever, because it’s Berlin, and will always be Berlin,” TOA’s organiser Niko Woischnik says in the comparative warmth of the festival venue, the former east German Funkhaus broadcast centre.

With over 150 international speakers and 175 satellite events on topics from sextech to the marketing practices of German hiphop to democratising VR, the festival showcases an understated confidence to the importance of tech – not just globally, but in terms of what the latest developments have to offer the city, as well as what sorts of start-ups could successfully be incubated here.


Although it champions the international perspective needed for success in the modern tech industry, Berlin is, as ever, determined to do things its own way. The thinking goes, instead of trying to outdo the Americans, why not work with the cultural and alternative capital Berlin has accrued over decades?

“There’s not the culture and diversity in Silicon Valley when it comes to different disciplines like music and art and so forth,” Woischnik says. He shrugs off the fact that the US tech centre is “60 years ahead of us” when it comes to IPOs. The city, he believes, has different things to offer.

Music-streaming platform Soundcloud is already headquartered in Berlin, and Spotify has a major office in the city. Start-up hubs such as Factory and growing amounts of blockchain activity have been gently nudging the Hauptstadt towards offering a one-of-a-kind tech centre with its own individual identity.

Reticence remains, however, among a local population angry at the gentrification of the formerly “arm aber sexy” (poor but sexy) capital into a 24-hour international tourist and business paradise. Tech companies have thus far avoided the ire directed at the Mediaspree development along the banks of the city’s central river. (These days, the Spree is home to the Universal Music and Viacom offices rather than the dwindling number of the community centres and excitingly ramshackle clubs which used to line its banks.) Is it just a matter of time?

Perhaps not, if the tech offered and developed in the city is as socially-minded as many of its proponents suggest. At TOA, the potential for coupling development with social good was underlined by proposals for better agricultural technology, or those which aimed to tackle the refugee crisis. Perhaps the growing tech cluster can reflect the city’s own character as well as Woischnik hopes, rather than offering low rents on glitzy offices to existing multinational corporations.

But while Berlin is Berlin, Germany is Germany. “Germany has been very... Traditionally very cautious about implementing change. And I think that it almost outweighs the times that this was for the benefit of the greater good,” Woischnik says with heavy diplomacy.

Uber’s restrictions, for one, are the result of national policy. Tensions between national wariness of change and Berlin’s wholehearted exuberance for it exist beyond the tech scene, of course: Germany is now lagging behind its EU partners in moving towards full legalisation of same-sex marriage, whereas Berlin’s credentials as a gay haven date back to Christopher Isherwood and beyond. The country may not be ready for a sextech capital, even if the capital itself is getting there.

Germany is not alone in Europe in its current divide in opinion between cosmopolitan, urban residents and its smaller towns and rural neighbourhoods: Brexit firmly exposed such divides in the UK, for whom a nascent and individual tech scene in Berlin could be a further blow to economic growth. With Berlin firmly planted in the heart of the EU, and with the free movement of people that goes with that, internationally-minded start-ups may increasingly favour the German capital over London.

"We are a very open city, so it’s not about the Brexit or you know, stealing away talent, or showing the UK it was a bad thing,” Woischnik says. Nonetheless, he offers encouragement to entrepreneurs heading for the German capital.

“I think that’s how this community here is being built, because it is built not just by Germans or people from Berlin, but it’s really built by people that come from all countries in the world...

"Let them come," he concludes. "Let the Brits in.”