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.

Imagine if there were a robotic fish that filtered microplastic out of the water as it swam. Well, now there is one, and it’s the physical version of the winning concept in the first-ever Natural Robotics Contest.

Announced this May, the University of Surrey’s Natural Robots Contest invited members of the public to give their concepts for animal—or plant-inspired robots capable of performing activities that would help the world.

Plans called for experts from various British and European research centers to select what they thought was the best concept, which would then be made into a real robot. Engineers would proceed to further develop the technology.

The winning concept turned out to be the plastic-collecting Robo-fish, designed by chemistry student Eleanor Mackintosh—who is a University of Surrey student. Mackintosh said, “Fish’s gills are an incredible mechanism in nature that are specialized to filter oxygen into the bloodstream—so I adapted my design from that, with the purpose of dealing with the plastic pollution in the water.”

The robot swims by moving its tail, holding its mouth wide open to-collect water and microplastics in its belly as it does so. Once that cavity is full, the robot closes its mouth, opens its gills, and pushes the water out through. A fine net attached to the gill flaps allows the water to pass through, but captures the microplastic.

In its current physical form, the 50-cm-long Robo-fish collects microplastic as small as 2 millimeters. It also uses sensors to monitor underwater environment, plus it tracks its movements within the water.

Future robots could capture much smaller particles. Other possible improvements include a faster body shape, a more powerful tail, and the ability to swim autonomously.

When you get a cut, you cover it with a bandage. How do you know when to change it? Maybe you just wait until it’s wet or dirty. But when people have long-term or chronic (慢性的)wounds that take months to get better, changing bandages too early or to late could make healing take even longer. Changing the dressing on a wound too often can provide an opportunity for infections to get in. But if a bandage gets very wet very quickly from the inside, it might be filling with pus (脓)--a sign an infection has begun. Judging just when to change is important.

Chronic wounds are common in people who are older or who have certain health conditions. Chronic wounds affect around 6.5 million people per year in the United States. When Anushka Naiknaware, 13, learned about chronic wounds, she decided to make a device that could alert a person when it’s time to change their bandages.

After a lot of trials and errors, the teen settled on a design that used an “ink” filled with carbon nanoparticles(纳米粒子). The teen loaded her ink into a printer cartridge (墨盒) to print onto her special paper, which was to be made into bandage. Well, actually, Anushka loaded her ink into many, many printer cartridges. Just changing a printer cartridge isn’t easy, and filling one is even harder.

The small printed papers cost only 5 to 10 cents, Anushka estimates. The Bluetooth sensor is more expensive, but the teen notes that it could be used over and over again. She also knows there is a long way to go before her design can help patients. It hasn’t been tested on a real person yet. “You have to make sure everything works perfectly,” she says.