Researchers at Cornell University are one step closer to building robots that are more like humans. This new method is one you might not expect. However, a soft robot muscle that "sweats" to regulate its temperature. "Sweating takes advantage of evaporated (蒸发)water loss to rapidly dissipate heat and can cool below the environmental temperature. So as is often the case, biology provided an excellent guide for us as engineers."

The fingerlike devices are 3D printed, water powered, and can be used to grab things. They are made of two soft chemical materials: a base layer of (CH₃) ₂ CH-C₃H₅ NO covered in a multihole layer of (C₃H₅ NO)_n. When the fingers reach a temperature of 30°C (86°F), the base layer reacts by shrinking, squeezing the water through the top pores (毛孔)in the top layer. The drying up is so efficient that the surface temperature of the actuator can drop by 21°C in just 30 seconds. That's three times more efficient than in humans. When wind from a fan is thrown into the mix, they cool down around six times as fast. The evaporation also cooled the object held by the actuator hand.

"The best part of this artificial strategy is that the heat regulation is based on the material itself," said T. J. Wallin, co-lead author, a research scientist at Facebook Reality Labs. "We did not need to have sensors or other components to control the sweating rate. When the local temperature rose above the set point, the pores would simply open and close on their own. "

While the result is exciting, it is only a first step. The robot has its weaknesses. The sweat can make the robot hand slippery, so the team is examining textures to improve its grasp. When the sweating takes place, the robot's mobility is also blocked and needs to refill its water supply.

"I think that the future of making these more biologically similar materials and robots is going to rely on the material composition," said co-lead author Rob Shepherd, an associate professor of mechanical and engineering. "This brings up a point about the importance of research involving several different academic subjects or areas, where really no one group has all the answers. "

China, the United Arab Emirates (UAE) and the United States plan to launch (发射) unpiloted spaceships in the next few weeks to fly to Mars. The operations are aimed at searching for signs of ancient, tiny life. Each country hopes the research will help them learn if astronauts could someday visit the red planet.

All the spaceships are expected to reach Mars next February after traveling about 485 million kilometers. Scientists want to find out what Mars was like billions of years ago, when it had rivers, lakes and Oceans, It is not by chance that the three launches are taking place soon. Mars and the earth are now in positions that favor such travel , permitting shorter travel time and less fuel use, The positioning happens about every two years.

The UAE spacecraft is named Amal, an Arabic word for hope. It is set to leave from Japan on Friday. The spacecraft will arrive at Mars in the year that the UAE marks the 50th anniversary of its founding: Controlled from Dubai , the spaceship will study the upper atmosphere of Mars and follow changes in its climate.

China will launch a rover (月球车) and an orbiter sometime around July 23. Chinese officials haven' t released much information about the operation, which is called Tianwen,or Questions for Heaven.

The USA plans to launch on July 30 from Florida. Perseverance, the NASA spaceship, will land in Jezero Crater, the site of an ancient river and lake. The area is Tull of large rocks ,cliffs and sand dunes (沙丘) - all possible threats to Perseverance. It will look for rocks that show signs of past life in the area. It will also test some of the technology that will be needed to send humans to the red planet and bring them home safely.

Police should be allowed to use facial recognition to investigate specific crimes and to protect the public at major events, according to the first national survey of the public's attitude to the technology. However, they are opposed to unrestricted use while two thirds (65 percent) of the public believe an absolute ban on the police would be wrong, Up to 70 percent backed its use to analyse faces on CCTV (闭路电视) to catch a suspect in an investigation or in day-to-day policing to prevent crime at events such as football matches or carnivals, The technology enables police to scan crowds and pick out faces that match huge databases of suspects.

There is, however, far less tolerance of its use by private (私人的) companies, whether to monitor shoppers or workers, or in schools if it was to be used to track children's behaviour or expressions. By a majority of almost two to one, the public believes that organizations should seek the permission of people before they start using facial recognition. Most also want a pause on any further use of the technology until publicly-agreed guidelines are in place on when and where it should be used.

More than half (55 percent) of the public believe the Government should limit police use of facial recognition to criminal investigations, though half also saw it as no different to taking photographs or using CCTV. Of those who were comfortable with its use, 80 percent said it was because it was “beneficial for the security of society”,

There was also a majority in favour of the technology where there was personal benefit, with 54 percent backing its use to unlock a smartphone by recognizing an owner’s face and with passport checks at airports where it can speed up queues.