【推荐2】The global sea level has risen by eight to nine inches since 1880. What’s more disturbing is that one-third of the rise in sea level happened in the last 25 years. Rising sea levels pose an existential threat for some small islands and some low-lying coasts. In a response to this threat, UN-Habitat, the Busan Metropolitan City of the Republic of Korea, and the company OCEANIX revealed the world’s first model floating city, OCEANIX Busan.

OCEANIX Busan has six integrated systems focusing on energy, food, water, waste, mobility and coastal habitat regeneration to ensure the floating city reuses and wastes as little as possible. The floating city has no roadways, only “pedestrian-friendly paths” to support walking, biking, and autonomous electric vehicles, so it won’t produce any vehicle emissions. Floating and rooftop photovoltaic panels(光伏板)will generate 100% of the operational energy needed for the city. Each neighborhood will treat and replenish(重新补充)its own water, recycle resources, and have urban farm areas to grow food.

OCEANIX Busan will consist of three floating neighborhoods totaling 15.5 acres. That’s about as much surface as a dozen football fields, and according to the developers, it has enough room to accommodate 12,000 people. The neighborhoods will connect to one another and the mainland via bridges, and each will serve a specific purpose. The living neighborhood will have residential buildings, shops and food sellers, and a “community backyard” where residents can gather at its center. The lodging neighborhood will be built to support visitors-it’ll have many shopping and dining options, as well as guest rooms designed to maximize ocean views. The third neighborhood will be a co-working and research center, with a temperature-controlled atrium(中厅)at its center for hydroponic agriculture.

“Today is an important milestone for all coastal cities and island nations on the frontlines of climate change. We are on track to delivering OCEANIX Busan and demonstrating that floating infrastructure can create new land for coastal cities looking for sustainable ways to expand onto the ocean, while adapting to sea-level rise,” said Philipp Hofmann, CEO of OCEANIX.

【推荐3】Cactus (仙人掌) leather is a bio-based material famous for its breathability, an area in which other vegan leathers fall short. This unique material has been used for handbags, shoes, clothes, and furniture. Even car companies are following the trend.

Cactus leather is made from the nopal cactus, which is harvested twice a year by cutting off only mature leaves so that the cactus can continue to grow. The leaves are then cleaned, broken into smaller pieces, and left out in the sun to dry. Fibers are separated from the dried pieces. Then, a powdered protein is extracted (提取), taken to a laboratory, and mixed with varying materials that include colorants to form a liquid substance, which is then poured on top of a carrier material to form cactus leather.

The nopal cactus used to make cactus leather is a fast-growing plant that doesn’t need much water. It is easily grown in dry conditions and is considered drought tolerant, an important quality for water conservation. Its hardiness also make it ideal in an industry that is reliant on whether and climate conditions, creating a good income source for farmers. The most promising part of cactus farming is the plant’s ability to store carbon in the soil, allowing it to play a part in dealing with climate change.

Leather has a long and troubled past. The poisonous substances used to make leather are often under fire as well as the treatment of animals. The cactus avoids these problems and also reduces carbon from the atmosphere. As the fabric is a relatively new, it is not known exactly how long it will last. That said, there is a study that shows the performance of the fabric is comparable to conventional leather.

Cactus leather appears to have a bright future ahead. Its adaptability and ability to draw in carbon are ideal features among the growing concerns for climate change and greenhouse gases.

【推荐2】Some bacteria(细菌)have a superpower that scientists would love to use. These bacteria gain energy from light, just as plants do.Scientists have wanted to use cyanobacteria(蓝藻菌)to make electricity. But in previous research, they didn’t survive long on artificial surfaces. Researchers have now moved them to a living surface — a mushroom. Their creation is the first mushroom to make electricity.

Applied Physicist Simon Jackson and his team turned that mushroom into a mini energy farm. This bionic(生物电子的)mushroom combines 3D printing, conductive ink and bacteria to generate electricity. Its design could lead to new ways of combining nature with electronics.

Like plants, cyanobacteria make their own food from sunlight, releasing electrons(电子). When enough electrons build up in one place, they can create an electric current.

The researchers needed to bring a lot of these bacteria together. They decided to use 3D printing to place them precisely onto a surface.Jackson’s team chose mushrooms for that surface. After all, they realized, mushrooms naturally host communities of bacteria and other microbes. Finding test subjects for their tests was easy. Jackson simply went to the grocery store and picked up white button mushrooms.

Printing on those mushrooms, though, turned out to be a real challenge. 3D printers have been designed to print on flat surfaces, but mushroom caps are curved. The researchers spent months writing computer code to solve the problem. Eventually, they came up with a program to 3D print their ink onto the curved mushroom tops.

The researchers printed two“inks”onto their mushrooms. One was a green ink made of cyanobacteria. They used this to make a spiral pattern on the cap. They also used a black ink made of graphene, which is great at conducting electricity. They printed this ink in a branching pattern across the mushroom top.

Then it was time to shine.

“Cyanobacteria are the real heroes here,”says Jackson. When his team shone light on the mushrooms, the bacteria gave out electrons. Those electrons flowed into the graphene and created an electric current.