This Robot Looks Like a Pancake and Jumps Like a Maggot能持续跳跃的扁平无腿机器人

萨布丽娜·伊布勒 云天

Researchers designed a soft， legless robot that can hop and navigate obstacle courses. 研究人員设计了一种可以跳跃和绕过障碍物的无腿软体机器人。

If a pancake could dream， it might long for legs so it could jump off your breakfast plate in pursuit of a better， unchewed life.

But legs， it turns out， are not necessary for something as flat as a flapjack to hop around. A group of scientists has designed a tortilla-shaped robot that can jump several times per second and higher than seven times its body height of half a centimeter. They report that the robot， which is the size of a squished1 tennis ball and weighs about the same as a paper clip， nimbly2 performs these feats without any semblance3 of feet.

Shuguang Li， a roboticist at Harvard who was not involved with the research， called the new robot “a clever idea” and “an important contribution to the soft robotics.”

Many terrestrial4 robots， meaning ones at home on the ground rather than in air or water， move by rolling or walking. But the ability to jump can help a terrestrial robot traverse5 new spaces and navigate rough terrain; sometimes its more efficient for a robot to jump over an obstacle than to go around it， Rui Chen， a researcher at Chongqing University in China and an author of the paper， wrote in an email.

Although jumping can offer some robots a competitive edge， engineering that ability has been a challenge for robotics researchers. Some soft robots that store energy can perform a single， impressive jump very infrequently. Some lightweight soft robots that do not store energy can hop about very frequently but cannot jump high or far enough to successfully cross an obstacle like a curb6.

The ideal jumping robot would be able to frequently jump high and far. But “these two pursuits are contradictory，” Dr. Chen said. Jumping higher or farther requires more energy， and jumping more frequently requires that energy to be accumulated and released over a shorter period of time—a tall task for a tiny robot.

For inspiration， the researchers looked to gall midge larvae， maggots that miraculously hurl themselves across distances 30 times as long as their loglike bodies， which are one-tenth of an inch long. “Most creatures need feet to jump，” Dr. Chen said， adding that the larvae “can leap by the bending of their bodies.” The maggot squishes itself into the shape of a ring—sticking its head to its rear with special sticky hairs—and squeezes fluid toward one end of its body， making it rigid. The accumulation of fluid builds up pressure， and releasing the pressure sends the maggot soaring.

The robots disklike body does not resemble that of a gall midge larva， but it jumps like one. Its body is made of two plastic pouches printed with electrodes7; the front pouch is filled with liquid and the rear is filled with the same volume of air. The robot uses static electricity to drive the flow of liquid to deform parts of its body， which causes the body to bend and generate force with the ground， resulting in a jump. And the air pouch mimics the function of an animals tail， helping the robot maintain a stable position while jumping and landing.

This design allows the robot to jump 7.68 times its body height and have a continuous jumping speed of six body lengths per second—a speed that Dr. Li called “very impressive.”

So the robot could jump rapidly and continuously. But could it cross obs-tacles？ To find out， the researchers put the tiny robot through numerous tests perhaps as deserving of an inspirational movie montage8 as Sylvester Stallones training in “Rocky9.”

The robot had to cross various gravel mounds， slopes and wires. It had to jump across a round step five milli-  meters tall and traverse an empty ring eight millimeters tall—monumental barriers for a four-millimeter-tall robot with a body like a pancake. The amateur acrobat passed all of these tests easily， if not gracefully.

The robot can also change directions on its own， around 138 degrees per second—the fastest turning speed of any soft jumping robot， Dr. Chen said. Much like a car， the robot can steer itself by continuously turning， according to Wenqi Hu， a senior research scientist at the Max Planck Institute in Germany who was not involved with the research.

The robot relies on external power that is fed through electrical wires. The researchers would like to make the robot wireless in future iterations10， but it will be a challenge to keep the robot tiny and lightweight， Dr. Chen said.

“I wonder if adding an onboard power source would be a challenge for this tiny soft jumper，” Dr. Li said.

The researchers propose integrating sensors into the tiny robot to allow it to detect environmental conditions， such as pollutants in buildings. Dr. Li suggested that the robot could eventually inspect hard-to-reach areas of large industrial machines or， if equipped with a small camera， be used on search-and-rescue missions for trapped people or animals， as it can travel through small spaces in disaster areas. And， he added， the robot is tiny and cheap. “It would probably cost only a few dollars to build one，” Dr. Li said.

Although the robot is currently confined to Earth， Dr. Hu suggested it might be right at home11 exploring another planet. “This type of task requires a simple but robust miniature robot design” that is lightweight enough to be carried to new worlds， Dr. Hu said， adding that the materials needed to build this robot would need to survive and function in extraterrestrial environments.

If this is true， the researchers robot might jump over dusty rocks and craters on the moon or Mars， going where no pancake has gone before.

如果一个早餐煎饼也能做梦的话，长出双腿可能是它渴求的梦想。这样它就可以从你的早餐盘上跳下来，以逃离被咀嚼的命运。

但事实证明，对于像煎饼一样扁平的东西来说，腿并不是跳来跳去的必要条件。一组科学家设计了一种煎饼形状的机器人，每秒可以跳跃数次，高度是其半厘米身高的七倍还多。报告指出，这个大小相当于一个被压坏的网球、重量与回形针差不多的机器人，没有双脚却可以灵活地完成这些壮举。

未参与此研究的哈佛大学机器人专家李曙光称，这种新型机器人是“一种奇思妙想”，“对软体机器人学做出了重要贡献”。

陆地机器人（即在家中的地面上而非空中或水中活动的机器人）大多通过滚动或行走来移动，但是跳跃的能力可以帮助地面机器人穿越新的空间并在崎岖的地形中确定行进方向。该论文的一位作者、中国重庆大学研究人员陈锐在一封电子邮件中称：对机器人来说，有时跃过障碍要比绕过障碍更高效。

虽然跳跃可以为一些机器人提供竞争优势，赋予机器人这种能力对机器人研究人员来说却是一个挑战。储能软体机器人可以进行强劲的跳跃，但频率很低;不储能的轻型软体机器人可以频繁地跳来跳去，但不能跳得足够高、足够远，从而成功越过路缘之类的障碍物。

理想的跳跃机器人能持续跳跃且跳得又高又远，但陈博士说“这两个目标是矛盾的”。跳得更高更远需要更多的能量，而持续跳跃则要求能量在较短时间内积累和释放：对于一个微型机器人来说，这是一项艰巨的任务。

为了获得灵感，研究人员研究了瘿蚊幼虫——这种蛆虫身体呈原木状、体长十分之一英寸，却能奇迹般地跳出30倍于体长的距离。“大多数生物需要脚才能跳跃，”陈博士说，这种幼虫“可通过弯曲身体来跳跃”。蛆虫将自己挤压成环形，用特殊的黏性毛发将头部黏在尾部并将液体挤压到身体的一端，使其变得僵硬。液体的积累会积聚压力，压力释放，蛆虫就会跃起。

机器人的盘状外形不似瘿蚊幼虫，但它们的跳跃方式如出一辙。它的主体由两个印有电极的塑料袋制成;前袋装满液体，后袋装满相同体积的空气。机器人利用静电驱动液体流动，使其身体某些部位弯曲并与地面产生反作用力，从而进行跳跃;装有空气的袋子则模仿了动物尾巴的功能，帮助机器人在跳跃和着陆时保持姿态稳定。

这种设计使机器人能跳到自身身高的7.68倍高度，每秒能持续跳跃体长的6倍距离。李博士称这一速度“十分了不起”。

机器人可以快速且持续地跳跃了。但它能跨越障碍吗？为了找到答案，研究人员对这个微型机器人进行了无数次测试——也许应该用蒙太奇手法剪辑一组鼓舞人心的电影画面，就像西尔维斯特·史泰龙在《洛奇》中的训练一样。

机器人需要穿过各种砾石堆、斜坡和电线。它得跳过一个五毫米高的圆形台阶，穿过一个八毫米高的空环——对于一个四毫米高、身体如煎饼般的机器人来说，这些是巨大的障碍;而业余杂技演员即使动作不优雅，也很容易通过以上的全部测试。

据陈博士所言，机器人也可以自己改变方向，大约每秒138度——这是软体跳跃机器人的最快转弯速度。德国马克斯·普朗克研究所的高级研究员胡文奇未参与此研究，他表示，机器人可以像汽车一样通过不断转弯来操纵自己。

机器人依赖通过电线输送的外部电源。据陈博士所言，研究人员希望在未来的迭代中使机器人无线化，但保持机器人小巧轻便将是一个挑战。

李博士则表示：“我想知道，对于这个小小的软体跳跃机器人来说，增加一个机载电源是否会是一个挑战。”

研究人员建议将传感器集成到微型机器人中，以使其能够检测环境因素，例如建筑物中的污染物。李博士认为，该机器人最终可以用于检查大型工业机器里难以够到的区域，如果配备了小型摄像头还可用于被困人员或动物的搜救，因为它能在灾区的狭小空间中行进。而且， 这种机器人很小、很便宜。“制作一个可能只需要几美元。”他补充说。

雖然此种机器人目前只能用于地球上，但胡博士认为，它有可能胜任探索其他星球。他说，“这类任务需要一种简单但坚固的微型机器人款式”，其设计要足够轻巧以便带到新星球，并补充表示，建造这种机器人所需的材料要能适应外星环境，并在该环境中正常运作。

倘若这能成真，研制的机器人可能会跃过月球或火星上布满灰尘的岩石和陨石坑，去到从未有煎饼涉足的地方。

（译者为“《英语世界》杯”翻译大赛获奖者）

1 squish压扁，挤扁。  2 nimbly敏捷地;灵巧地。  3 semblance表象，外观。

4 terrestrial地面的，陆地的。  5 traverse穿过;横穿。  6 = kerb〈英〉（道路的）路缘。

7 electrode电极。

8 montage〈法语〉蒙太奇，原为建筑学术语，意为构成、装配，现多指一种电影剪辑技术，是电影创作的主要叙述手段和表现手段之一。蒙太奇相对于长镜头电影表达方法，它通过将一系列不同地点、不同距离、不同角度、不同方法拍摄的短镜头组合使用来编辑成一部有情节的电影。  9《洛奇》讲述了一名拳击手（西尔维斯特·史泰龙饰）为争夺拳王不懈练习的故事，电影中多次运用了蒙太奇的表现手法。  10 iteration迭代。