Scientists estimate that more than 95 percent of Earth’s oceans have never been observed, which means we have seen less of our planet’s ocean than we have the far side of the moon or the surface of Mars. The high cost of powering an underwater camera for a long time, by tying it to a research boat or sending a ship to recharge its batteries, is a steep challenge preventing widespread undersea exploration.

MIT researchers have taken a major step to overcome this problem by developing a battery-free, wireless underwater camera that is about 100,000 times more than other undersea cameras. The device takes color photos, even in dark underwater environments, and transmits image data wirelessly through the water.

The autonomous camera is powered by sound. It transforms mechanical energy from sound waves traveling through water into electrical energy that powers its imaging and communications equipment. After capturing and encoding (编码) image data, the camera also uses sound waves to transmit data to a receiver that reconstructs the image.

Because it doesn’t need a power source, the camera could run for weeks on end before retrieval, enabling scientists to search remote parts of the ocean for new species. It could also be used to capture images of ocean pollution or monitor the health and growth of fish raised in aquaculture farms.

“One of the most exciting applications of this camera for me personally is in the context of climate monitoring. We are building climate models, but we are missing data from over 95 percent of the ocean. This technology could help us build more accurate climate models and better understand how climate change impacts the underwater world,” says Fadel Adib, associate professor in the Department of Electrical Engineering and Computer Science.

Earthquake rescue robots have experienced their final tests in Beijing. Their designers say that with these robots, rescue workers will be able to have more time to save more lives during an earthquake.

This robot looking like a helicopter, is called the detector­bot. It’s about 4 meters long, and it took about 4 years to develop the model.   Its main functions (作用) are to collect information from the air, and send goods of up to 30 kilos to people stuck in an earthquake.

This robot has a high quality 360 degree panoramic (全景的) camera. It can work day and night and will also be able to send the latest pictures from the quake area. Dr. Qi Juntong, from the Chinese Academy of Sciences, said, “Unlike other automatic machines, the most important feature of this robot is that it doesn’t need a distant control. We just input the information of the earthquake­struck area to it, and then it   takes off, and lands by itself. It flies as high as 3,000 meters,   and as fast as 100 kilometers per hour.”

This robot has a different function — it can change as the   environment changes. Its main job is to search for any signs of   life in places where human rescuers are unable to go.

As well as a detector (探测器) that finds victims (遇难者) and detects poisonous gas, a camera is placed in the 4­meter­long robot, which can work in the dark.

Another use for the rescuers is the supply device, with its 10­meter­long pipe. People who are caught in the ruins will be able to get supplies including oxygen and liquids.

Experts have said that the robots will go into production,   and serve as part of the national earthquake rescue team as soon as next year.

Singapore researchers say they have developed a form of electronic skin that can create a sense of touch. They hope their invention will give people with prosthetic hands (假肢手) the ability to identify different objects.

The skin device measures 1 square centimeter. The system contains 100 small sensors that attempt to recreate things like texture (质地), temperature and even pain. The researchers call the device Asynchronous Coded Electronic Skin, or ACES, which can process information faster than humans' nervous system. Machine learning methods trained the device to recognize 20 to 30 different textures. It can even correctly read Braille letters most of the time, the researchers say.

The system does not require the users' movement to work. Humans need to slide to feel texture. But in this case the skin, with just a single touch, is able to detect textures of different roughness.

A demonstration showed that the device could identify the difference between a soft ball and a solid plastic one. “When you lose your sense of touch, you essentially become numb and prosthetic users face that problem,” said Benjamin Tee, leader of the research team. “So by recreating an artificial version of the skin, for their prosthetic devices, they can hold a hand and feel the warmth and feel that it is soft.”

Tee said his idea for the device came from the movie Star Wars, when character Luke Skywalker loses his right hand and it is replaced with a robotic one. In the film, the new hand is able to experience touch sensations just like the real one.

The artificial skin technology is still going through experiments and development. But Tee said there had already been a lot of interest in the system, especially from the medical community. Tee said similar inventions that his team has developed include see-through skin that can repair itself when torn and a material for wearable electronic devices that gives off light.