What if our city streets could act like forests and reduce pollution? Thanks to scientific innovation, roads treated with a new pavement technology can now literally eat smog and help keep cities cool. Since there is little room for forests in urban areas, where air pollution actually occurs, Pavement Technology Inc. (PTI), together with researchers from Louisiana State University, came up with an asphalt spray (沥青喷雾) called A. R. A. -1 Ti.

The spray's exact composition hasn't been revealed, but it is known to be based on titanium oxide (二氧化钛), a component contained in many sunscreens on the market. This chemical substance acts as a photocatalyst, so when ultraviolet rays (紫外线) from the sun activate its electrons, light and heat are absorbed and moved apart. Through a chemical process, titanium oxide also breaks down poisonous substances in the air. “In good conditions, we can achieve a 60% reduction”, said Michael Durante, PTI's vice president of finance and strategic planning. But the spray is not only meant to address overheating and to remove harmful gases produced by cars. It can also make aging asphalt stronger, preventing breaks generated by severe heat, the Ohio-based firm states, according to Gizmodo.

This impressive list of properties has encouraged several cities in the US to try out the product. The success stories keep adding up. At Orlando International Airport, taxiway pavements that had been sprayed with the titanium dioxide-based composition have already managed to reduce nitrogen oxide rates by half. And in Charleston, the pavement treatment is being used in low-income neighborhoods that have many asphalt-coated roads.

The company suggests that while heat shortens pavement life, their product's components can extend it from five to ten years, which translates the pavements into sustainable roads. And although green spaces are still necessary and cannot be fully replaced due to their multiple environmental and health benefits, innovations like A. R. A. -1 Ti are extremely promising. We may expect to see the major benefits it can bring to public health, positively impacting the lives of billions living in urban areas worldwide.

Scientists have designed plenty of devices that can pick up solid objects. Big mechanical claws can lift cars. Small claws can pluck (摘，拉) prizes from a glass box in an arcade game (街机游戏). But these new pluckers can lift something else entirely — a liquid.

Engineers have built the device, which can pick up and move a single drop of liquid. The device is made of two flexible crossed pieces. It is about the size and shape of a finger. Experimental tests showed that the pair can lift up a drop of liquids as small as 2 millimeters (0.08 inch) across.

Such a device might help scientists safely handle biological liquids like blood, says Arun Kota. That task could be particularly useful in laboratories where samples are tested for signs of flu or other infectious diseases. Kota is a mechanical engineer at North Carolina State University in Raleigh. He worked on these new devices.

The new device combines tech from two fields of engineering. One is soft robotics. Unlike robots made from hard and heavy materials such as metal, soft robots are made from soft stuff. The other field is materials science. “Many materials are repellent to water, but in alcohol or oil they’re no longer able to do it,” Kota says. Working with Wei Wang, an engineer in his lab, he developed such materials, which will not let any liquid pass through them.

The group completed their design by 2017. Yet cool as it was, it had no obvious use. Xiaoguang Dong, an engineer at Vanderbilt University, doubts whether infectious disease labs are looking for such a device. “To me, this is not really practical,” he says. “The number of droplets that can be lifted is very small. They need independently robotic fingers to lift several droplets. If you want to control hundreds of droplets, how do you do that?”

The world’s elderly population is increasing. The number of older people — those age 60 years or older — is expected to double by 2050 and is growing faster than all younger age groups across the globe. That comes with an increasing need for caregivers which can provide 24-hour care, not only at hospitals or nursing homes, but also at private homes.

Already, caregiving robots are programmed to ask questions a nurse would ask and can keep an eye on patients for falls These robotic assistants are expected to become increasingly marketable and reach 450,000 by 2045 because of the expected caregiver shortage in the USA.

“Unluckily, the hard structure of present caregiving robots prevents them from a safe human-robot interaction (互动), limiting their assistance to only social interaction and not Physical interaction,” said Ramses Martinez,an assistant professor in Purdue’s College of Engineering. “After all,would you leave babies or old people in the hands of a robot?”

Recent advances in material science have enabled the production of soft robots with deformable (可变形的) bodies or the ability to reshape when touched, but today the complex (复杂的) design prevents the use of this technology at home.

However, Martinez and other researchers have developed a new design method which shows promise in enabling the production of soft robots using a 3D printer.

The design process has three steps. First, a user makes a computer-aided design file (文件) with the shape of the robot. The user then paints the file to show which directions the different joints of the soft robot will move. It takes the computer a few seconds to change the computer-aided model into a 3-D soft machine that can be printed using any 3-D printer.

“The soft machines move like humans. Their ability to change their body structure and movement to adapt (适应) to a wide variety of environments will improve caregiving greatly.” says Martinez.

The researchers are looking for partners to test and bring their technology to market.