More than half of the world’s population live in cities, and by 2050 the UN expects that proportion to reach 68%. This means more homes, roads and other infrastructure. In India alone, a city the size of Chicago will have to be developed every year to meet demand for housing. Such a construction increase is a bad sign for dealing with climate change, because making steel and concrete, two of the most common building materials, generates around 8% of the world’s CO₂ emissions (排放). If cities are to expand and become greener at the same time, they will have to be made from something else.

Wood is one of the most promising sustainable alternatives to steel and concrete. It is not, however, everyday wood that is attracting the interest of architects.

Rather, it is a material called engineered timber. This is a combination of different layers, each designed to meet the requirements of specific parts such as floors, panels and beams (横梁). Designers can use it to provide levels of strength like steel, in a product that is up to 80% lighter. In addition, engineered timber is usually made into large sections in a factory for future use, which reduces the number of deliveries to a construction site.

According to Michael Ramage of the University of Cambridge, a wooden building produces 75% less CO₂ than a steel and concrete one of the same size. However, if building with wood takes off, it does raise concern about there being enough trees to go round. But with sustainably managed forests that should not be a problem, says Dr Ramage. A family-sized apartment requires about 30 cubic meters of timber, and he estimates Europe’s sustainable forests alone grow that amount every seven seconds. Nor is fire a risk, for engineered timber does not burn easily. Besides, fireproofing layers can be added to the timber. All in all, then, it looks as if wood as a building material may get a new lease of life.

A Japanese start-up called Ashirase is stepping into the global market with a new navigation (导航) assistance product intended to help people with low vision.

Its new product will feature flexible vibrating (震动) bases around each foot and are put into each shoe, and a small pack that can be removed for charging (充电). Once fitted, the vibrating parts are set along the sensitive nerves on the foot and can send coded walking instructions to the user.

Its present form navigates a route that comes from a smartphone app. It can help clear up distractions by freeing up the attention that is normally needed to either listen to voice directions or check the phone. Visual-damaged users can use their hearing to listen to traffic sounds and signals, like warning beeps at crossings or sidewalks, and use their hands to carry walking sticks or other belongings.

The device is paired with an app through a Bluetooth connection. The app uses information from Google Maps or similar vendors to draw up a walking route to the destination. Based on the destination and how the user is walking, it will send signals to the device that will cause a vibration on the foot.

The device will vibrate at a regular frequency at the front of the foot to let the users know they’re on the right track and should keep going straight. It will speed up the vibrations once the user is approaching a turn and needs to stop, and it will vibrate in either the left or right shoe to signal the direction the user needs to turn.

Ashirase’s new tech is waterproof and washable. It can be charged at the end of the week to power through seven days of walking, accounting for three active hours each day. And it can be fitted in two types of shoes: sneakers and leather lace-up shoes.

An Austrian company Tec-Innovation recently showed smart shoes that use ultrasonic sensors (超声波传感器) to help people suffering from vision impairment to discover obstacles(障碍) up to four meters away.

Known as InnoMake, the smart shoe aims to replace the decades-old walking stick that millions of people around the world depend on to get around as safely as possible. The currently available model relies on sensors to detect obstacles and warns the wearer through shaking and a loud alert sounded on a bluetooth-linked smartphone. That sounds impressive enough, but the company is already working on a much more advanced version that incorporates cameras and artificial intelligence to not only detect obstacles but also their nature.

“Not only is the warning that I am facing an obstacle relevant, but also the information about what kind of obstacle I am facing. Because it makes a big difference whether it’s a wall, a car or a staircase.” Markus Raffer, one of the founders of Tec-Innovation, told TechXplore.

”Ultrasonic sensors on the toe of the shoe detect obstacles up to four meters away. The wearer is then warned by vibration and/or acoustic signals. This works very well and is already a great help to me personally.” Raffer, himself visually impaired, added.

The current version of the InnoMake shoe is already available for purchase on the Tec-Innovation website, for €3,200 per pair.

The advanced system is integrated in the front of the shoes, in a waterproof and dustproof case. It is powered by a heavy-duty battery that can last for up to one week, depending on use. The battery can be charged in just three hours, using a USB cable.

The next step for Tec-Innovation is to use the data collected by its system to create a kind of street view navigation map for visually impaired people.

“As it currently stands, only the wearer benefits in each case from the data the shoe collects as he or she walks. It would be much more sustainable if this data could also be made available to other people as a navigation aid,” computer scientist Friedrich Fraundorfer explained.