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”.

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San Francisco now has a taxi app for kids

"See you later, Mom - I'm off to get a ride from a complete stranger." Image: Shuddle.

While using taxis for the school run might sound a little extravagant, most parents would agree that, on occasion, it would be nice to palm a lift off to someone else - even if it means paying them. Last September, The New York Times reported that parents are increasingly shuttling their children around in Uber taxis. 

The problem is, parents of younger children may not feel comfortable sending them off in a car with a total stranger. Enter new app Shuddle (presumably a portmanteau of shuttle and cuddle? Or huddle? Muddle?), which is providing a specialised taxi service for children in San Francisco. The cars are driven by "childcare specialists" who must have experience in childcare, undergo background checks and receive additional training.

The service launched yesterday, and operates, like most new car-hire services, through an app. However, Shuddle doesn't come with quite the same benefits as other app-based services: you must book cars at least a day in advance, and users pay a monthly $9 fee on top of charges per ride.

Perhaps as a result of the childcare requirement, all 100 of the app's drivers are women. This is very uncommon for taxi services - in New York, 1 per cent of yellow taxi drivers are women, which led Stella Mateo to found SheRide, which provides female drivers to female passengers. 

The gender shift in new taxi services may also be a product of a trend towards personalisation. SheRide is for women who want women drivers; Shuddle is for parents who want drivers with childcare experience. At a recent keynote event for Hailo, the black cab taxi app, one speaker predicted that this trend may go even further, with in-app user profiles listing your preferences: 

As you step into the cab, they will have an idea of your likes, dislikes and interests. The in-cab media will be showing you a relevant TV channel. Or maybe you want to work, in which case you’ll be offered a quiet, undisturbed journey. Perhaps you are planning to catch-up your favourite team’s game on TV when you get home? The driver will know you don’t want to hear the score.

This might be going a little far. Call us old-fashioned, but cabbies wouldn't be cabbies if they weren't talking your ear off about their favourite topics, irrespective of your interest (or lack thereof). 

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