This Robot Looks Like a Pancake and Jumps Like a Maggot能持續跳躍的扁平無腿機器人

薩布麗娜·伊布勒 云天

Researchers designed a soft， legless robot that can hop and navigate obstacle courses. 研究人員設計了一種可以跳躍和繞過障礙物的無腿軟體機器人。

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.

如果一個早餐煎餅也能做夢的話，長出雙腿可能是它渴求的夢想。這樣它就可以從你的早餐盤上跳下來，以逃離被咀嚼的命運。

但事實證明，對于像煎餅一樣扁平的東西來說，腿并不是跳來跳去的必要條件。一組科學家設計了一種煎餅形狀的機器人，每秒可以跳躍數次，高度是其半厘米身高的七倍還多。報告指出，這個大小相當于一個被壓壞的網球、重量與回形針差不多的機器人，沒有雙腳卻可以靈活地完成這些壯舉。

未參與此研究的哈佛大學機器人專家李曙光稱，這種新型機器人是“一種奇思妙想”，“對軟體機器人學做出了重要貢獻”。

陸地機器人（即在家中的地面上而非空中或水中活動的機器人）大多通過滾動或行走來移動，但是跳躍的能力可以幫助地面機器人穿越新的空間并在崎嶇的地形中確定行進方向。該論文的一位作者、中國重慶大學研究人員陳銳在一封電子郵件中稱：對機器人來說，有時躍過障礙要比繞過障礙更高效。

雖然跳躍可以為一些機器人提供競爭優勢，賦予機器人這種能力對機器人研究人員來說卻是一個挑戰。儲能軟體機器人可以進行強勁的跳躍，但頻率很低;不儲能的輕型軟體機器人可以頻繁地跳來跳去，但不能跳得足夠高、足夠遠，從而成功越過路緣之類的障礙物。

理想的跳躍機器人能持續跳躍且跳得又高又遠，但陳博士說“這兩個目標是矛盾的”。跳得更高更遠需要更多的能量，而持續跳躍則要求能量在較短時間內積累和釋放：對于一個微型機器人來說，這是一項艱巨的任務。

為了獲得靈感，研究人員研究了癭蚊幼蟲——這種蛆蟲身體呈原木狀、體長十分之一英寸，卻能奇跡般地跳出30倍于體長的距離。“大多數生物需要腳才能跳躍，”陳博士說，這種幼蟲“可通過彎曲身體來跳躍”。蛆蟲將自己擠壓成環形，用特殊的黏性毛發將頭部黏在尾部并將液體擠壓到身體的一端，使其變得僵硬。液體的積累會積聚壓力，壓力釋放，蛆蟲就會躍起。

機器人的盤狀外形不似癭蚊幼蟲，但它們的跳躍方式如出一轍。它的主體由兩個印有電極的塑料袋制成;前袋裝滿液體，后袋裝滿相同體積的空氣。機器人利用靜電驅動液體流動，使其身體某些部位彎曲并與地面產生反作用力，從而進行跳躍;裝有空氣的袋子則模仿了動物尾巴的功能，幫助機器人在跳躍和著陸時保持姿態穩定。

這種設計使機器人能跳到自身身高的7.68倍高度，每秒能持續跳躍體長的6倍距離。李博士稱這一速度“十分了不起”。

機器人可以快速且持續地跳躍了。但它能跨越障礙嗎？為了找到答案，研究人員對這個微型機器人進行了無數次測試——也許應該用蒙太奇手法剪輯一組鼓舞人心的電影畫面，就像西爾維斯特·史泰龍在《洛奇》中的訓練一樣。

機器人需要穿過各種礫石堆、斜坡和電線。它得跳過一個五毫米高的圓形臺階，穿過一個八毫米高的空環——對于一個四毫米高、身體如煎餅般的機器人來說，這些是巨大的障礙;而業余雜技演員即使動作不優雅，也很容易通過以上的全部測試。

據陳博士所言，機器人也可以自己改變方向，大約每秒138度——這是軟體跳躍機器人的最快轉彎速度。德國馬克斯·普朗克研究所的高級研究員胡文奇未參與此研究，他表示，機器人可以像汽車一樣通過不斷轉彎來操縱自己。

機器人依賴通過電線輸送的外部電源。據陳博士所言，研究人員希望在未來的迭代中使機器人無線化，但保持機器人小巧輕便將是一個挑戰。

李博士則表示：“我想知道，對于這個小小的軟體跳躍機器人來說，增加一個機載電源是否會是一個挑戰。”

研究人員建議將傳感器集成到微型機器人中，以使其能夠檢測環境因素，例如建筑物中的污染物。李博士認為，該機器人最終可以用于檢查大型工業機器里難以夠到的區域，如果配備了小型攝像頭還可用于被困人員或動物的搜救，因為它能在災區的狹小空間中行進。而且， 這種機器人很小、很便宜。“制作一個可能只需要幾美元。”他補充說。

雖然此種機器人目前只能用于地球上，但胡博士認為，它有可能勝任探索其他星球。他說，“這類任務需要一種簡單但堅固的微型機器人款式”，其設計要足夠輕巧以便帶到新星球，并補充表示，建造這種機器人所需的材料要能適應外星環境，并在該環境中正常運作。

倘若這能成真，研制的機器人可能會躍過月球或火星上布滿灰塵的巖石和隕石坑，去到從未有煎餅涉足的地方。

（譯者為“《英語世界》杯”翻譯大賽獲獎者）

1 squish壓扁，擠扁。? 2 nimbly敏捷地;靈巧地。? 3 semblance表象，外觀。

4 terrestrial地面的，陸地的。? 5 traverse穿過;橫穿。? 6 = kerb〈英〉（道路的）路緣。

7 electrode電極。

8 montage〈法語〉蒙太奇，原為建筑學術語，意為構成、裝配，現多指一種電影剪輯技術，是電影創作的主要敘述手段和表現手段之一。蒙太奇相對于長鏡頭電影表達方法，它通過將一系列不同地點、不同距離、不同角度、不同方法拍攝的短鏡頭組合使用來編輯成一部有情節的電影。? 9《洛奇》講述了一名拳擊手（西爾維斯特·史泰龍飾）為爭奪拳王不懈練習的故事，電影中多次運用了蒙太奇的表現手法。? 10 iteration迭代。