9 . Soap (肥皂) might seem like a reasonable way to avoid mosquito bites (蚊子叮) on the basis that if mosquitoes can’t smell you, they can’t bite you. However, a recent study has found that rather than protecting you, certain soaps might actually make you more attractive to mosquitoes.

In the study, conducted at Virginia Polytechnic Institute and State University, four volunteers were asked to wear a sleeve before and after washing with four different brands of soap. The researchers then watched female mosquitoes as only females feed on blood landing on the fabric sample to show their preference. They found that some people washing with some brands of soap, increased their attractiveness to mosquitoes, while washing with other brands of soap tended to repel (驱除) mosquitoes. The repellent effect of some soap may be due to its coconut scent, as coconut oil is known to act as a natural mosquito repellent. The reason behind this attraction is believed to be related to mosquitoes’ sugar intake. When mosquitoes are not feeding on blood, they add their diet with plant juice or sweet water from flowers, “The fact we are taking those flowery and fruity smells and putting them on our bodies means that now the same object smells like a flower and a person at the same time,” said Clément Vinauger, who led the study. It would be like waking up and smelling the smell of coffee and bread, very attractive.

Interestingly, the effects of the soap varied among people, possibly due to the interaction (相互作用) between the soap and each person’s unique body scent. “It’s remarkable that the same person that is extremely attractive to mosquitoes when he is unwashed, but he becomes even more attractive to mosquitoes with one soap, and then become repellent to mosquitoes with another soap,” said Vinauger. Further research is needed to better understand the interaction between different soap and body scents, as well as to develop more effective mosquito repellents.

10 . The design theory behind a pair of tiny robots may one day find its way into environmental monitoring, as well as search and-rescue tasks. Modeled after a water strider (水黾), an insect, the two robots each weigh in at 8 and 55 milligrams, and may mark the smallest, lightest, and fastest fully functional micro-robots in the world, according to Washington State University (WSU).

Developed by a team of WSU researchers, the robots’ tininess largely relies on a material known as a shape memory alloy (合金). Although shape memory alloys change form when heated, they can “remember” their original shapes and return to them after cooling. Because of this, the two micro-robots do not require standard motors, and they use light and small ones instead of bulky moving parts.

Both the robots’ motors are each made up of two shape memory alloys, allowing them to move their fins as fast as 40 times a second while also lifting over 150 times their weight. “They’re very technologically sound. The development of the very lightweight robots opens up new possibilities in micro-robotics,” said Conor Trygstad, a material engineering PhD student and study lead author. “Although the robots are impressive when compared to other robots, the pair still fall behind their biological relatives’,” Trygstad said. They can currently move at a speed of about six millimeters a second; a water strider, by comparison, speeds along at about a meter per second. For now, the robots also require wired (连线的) power sources, thus seriously preventing any real-world applications for the moment.

Going forward, however, the team plans to copy other small insect species while also creating a new water strider robot which can move at a higher speed. Depending on using small batteries could also greatly increase the robots’ areas of use, If the breakthrough designs continue improving, similar micro-robots could one day be employed to monitor hard-to-reachor dangerous environments.