All posts by Lucy Ingham

Illuminating the underbelly: the reflection technology set to light up narrow city streets

Dark ground-level alleys and streets in skyscraper-filled cities could soon be a thing of the past, as a team of researchers in Egypt have developed a light-directing panel that reflects natural sunlight into dark streets.

The panel is attached to the edge of rooftops and positioned at an angle so that it reflects sunlight into the street, meaning dark alleys can enjoy the benefits of natural sunlight without the need for complicated light-tracking devices or an electricity supply.

As cities have increasingly looked to the sky to expand, the number of ground-level areas lacking sunlight is on the rise, and this trend is only set to continue.

Pressure on space is so severe that before long some regions could embrace multi-level cities not unlike Hengsha in the cyberpunk videogame Deus Ex: Human Revolution, resulting in poorly lit lower areas that are likely to be a target for crime.

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However, with this technology these areas could once again access natural sunlight, providing a far better alternative to neon or fluorescent light, and generally improving the living standards ground-level areas.

“We expect the device to provide illumination to perform everyday tasks and improve the quality of light and health conditions in dark areas,” said professor of electronics and communications engineering at Ain Shams University in Cairo, Egypt, Amr Safwat.

Safwat also highlighted the health conditions associated with inadequate sunlight, including depression, loss of energy and serious mood changes. “Research has shown that lack of natural lighting can cause severe physiological problems,” he added.

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Although similar technology has been used to bring natural light to poorly-lit rooms, this is the first time such a device has been developed for outdoor street environments.

The panel is made of an acrylic plastic also used to make Plexiglas, which is smooth at the bottom but covered in ridges at the top. The ridges are based on a sine wave, and have been shaped to distribute the maximum amount of sunlight on the street below.

As the panels require no electricity they are a surprisingly cost-effective way to boost light in dark streets.

Safwat said that the panel, which is still in the testing phase, is likely to cost between $70 and $100 per square meter, making it cheaper and greener than some other electricity-based solutions. And with plans to commercialise the technology, these panels could soon be a familiar sight in cities around the world.


Inline images courtesy of Optics Express.


Self-Healing Plastics: Materials that Can Restore Their Molecular Structure

Plastics have found their way into an incredible number of items in our lives, from cars and gadget cases to furniture and accessories, but they have traditionally been seen as ‘cheap’ materials because of their easy-to-scratch finish.

This could soon be changing, as scientists from Karlsruhe Institute of Technology (KIT) have developed a way of creating plastics with a built-in self-healing method to repair cracks, scratches and other damage.

The molecules in the plastic are linked together by a reversible chemical reaction, turning them into something called a switchable network that can be broken down into its constituent materials and then reassembled again.

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This process can be initiated just by using heat, light or a chemical substance, making it a straightforward method for use in non-lab situations.

“Our method does not need any catalyst, no additive is required,” said KIT group leader Professor Christopher Barner-Kowollik.

Not all plastics can be used, but in a press release KIT confirmed that the “self-healing properties can be transferred to a large range of plastics known”. Of those, healing can be triggered within a very short time at temperatures between 50°C to 120°C.

Most of the research has been to speed up the time healing takes and to confirm that the plastic’s original strength and tension could be completely restored. In some instances the team has been able to improve material strength with the process.

“We succeeded in demonstrating that test specimens after first healing were bound even more strongly than before,” said Barner-Kowollik.

The technology can also be used to mould plastics, which could potentially make it a rival for 3D printing – the scientists have suggested that the technology could be used to produce reinforced plastic components for aircrafts and vehicles.

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The technology could turn plastic into a far more valuable and durable material – it would no longer be so firmly associated with a throwaway culture if it could heal itself, which could result in less waste from plastics.

One of the best potential applications of this would be for vehicle chassis – scratches and chips could be fixed within seconds using just a hairdryer.

Similarly, phone cases, apparel and wearables could all benefit – being able to easily heal your product would keep it looking new long after it had been bought, which could again result in a less throwaway approach to these gadgets and items.


Inline images courtesy of Esther Simpson and Henning Mühlinghaus.