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Scientists have long had it in their mind to make a robot lizard (蜥蜴). They began with finding out why a lizard can hang on a wall. They noticed the lizard’s toes were unique: They have suckers (吸盘), which enable it to hang on walls. They, therefore, made a robot with suckers on its hands and feet.
The robot could hang on the wall but fell off when crawling. So, they went on researching. 6 years ago, scientists discovered that suckers only were not enough. It is the bristles (刚毛) on each foot that adds friction (摩擦) and static adsorption (静电吸附力) that makes a lizard move on the smooth wall easily without falling down.
Then scientists made great efforts to fix thick bristles to the robot’s hands and feet. However, the effect was not satisfactory. The robot still couldn’t attach itself firmly to the wall.
Scientists got puzzled: How on earth can the lizard crawl on an extremely smooth wall or even on a ceiling without dropping off?