May 6, 2013Seahorse tails may hold key to flexible robotic tentacles

Seahorse tails are prehensile, like a monkey's (Photo: shellac)

Image Gallery (3 images)

The meaning of the word biomimicry is being devalued and inflated, to the point that any technology or design with the vaguest resemblance to something in the natural world tends to have the word unthinkingly applied to it. PR people in the automotive and architectural fields are now particularly fond of the word. So it's refreshing to be able to report on some research that has taken a detailed look at a natural phenomenon, the armor of a seahorse, and thought about how it might be applied in the field of robotics. The researchers think a similar structure of sliding plates could be used to improve robot arms used for underwater exploration and bomb disposal.

Though the seahorse isn't the only armored creature on Earth, it is perhaps the most flexible. Its monkey-like prehensile tail allows it to hook onto corals and seaweed. But the researchers wondered whether the armor provides protection from crushing, which is the favored mode of attack used by its natural predators, which include crabs and turtles. By compressing sections of seahorse tails, the researchers found that these could be compressed down to just over half the original width without permanent damage occurring. The tail needed to be compressed by over 60 percent before the spinal column was permanently damaged, with connective tissues and tail muscles absorbing most of the compression. (The seahorses used were already dead.)

The tail of a seahorse comprises 36 segments which get smaller and smaller towards the end of the tail. Each segment is a square-like shape made up of four L-shaped plates, which can both pivot and glide over one another. They are connected to the spinal column by connective tissue. It's this structure that accounts for the great flexibility of the tail.

The structure of a seahorse tail (Image: Joanna McKittrick research group/Jacobs School of Engineering at UC San Diego)

The researchers are using 3D printing to replicate the structure of the plates, which would be attached to polymers to simulate muscles. The intent is to build a robotic arm that synthesizes hard and soft materials (unlike many other robotics projects, which the researchers say tend to favor either one or the other). By creating an arm similar to the tail of a seahorse, researchers think the arm would be able to grasp objects of varying size, rather like a robotic tentacle. How might such an arm be used? Medical devices, exploring the oceans and bomb disposal are all potential uses, the researchers say.

Armor isn't the only interesting thing about seahorses, a genus of fish (Hippocampus) containing 54 known species. They're something of a faunal curiosity shop. "Seahorses are unique in that they have a head like a horse, a long tubular snout like an anteater, a prehensile tail like a monkey, a brood pouch like a kangaroo, camouflage skin like a flounder, and eyes that move independently like a chameleon," said Michael Porter of the Jacobs School of Engineering at UC San Diego where the research took place. "We studied the prehensile tail because [of] its gripping and grasping ability, and it's protected by the natural armor." For their research, the team looked at the common seahorse, Hippocampus kuda.

The team's research appeared in the journal Acta Biomaterialia. You can see a video showing a prototype of the simulated sliding plates in the video below.

海马尾巴可以抓握韧性机器人的关键部分

5月6日2013Seahorse尾部可容纳关键灵活的机器人tentacles

海马尾巴抓握，像一只猴子的（照片：虫胶）

图片廊（3图像）

字仿生学的意义正在贬值，充气，以任何技术或设计与模糊的相似的东西在自然界中往往具有不假思索适用于它的话点。公关人在汽车和建筑领域现在特别喜欢这个词。所以它的清爽能够在一些研究已经采取了详细讨论一个自然现象，海马的装甲，并认为它如何可能会在机器人技术领域的应用报告。研究人员认为滑板的类似的结构可以用来改善用于水下探测和拆弹机器人??手臂。

虽然海马是不是地球上唯一的装甲生物，它也许是最灵活的。其猴子般的抓握尾巴允许它钩住珊瑚和海藻。但研究人员想知道的盔甲无论是从粉碎，这是攻击所用的天敌，包括螃蟹和乌龟偏爱的模式提供了保障。通过压缩海马尾部部分，研究人员发现，这些可以被压缩到刚刚超过一半的原始宽度没有永久的伤害发生。所需的尾要超过60％的被压缩前的脊柱被永久损坏，有结缔组织和肌肉尾吸收大部分的压缩。 （所用的海马已经死了。）

一个海马的尾部包含36段而变得越来越小朝尾巴末端。每个段是一个正方形状由四个L形板，它可以同时枢轴和滑过另一个。它们连接到由结缔组织脊柱。正是这种结构占的尾巴很大的灵活性

的海马尾部的结构（图片：乔安娜McKittrick研究小组

工程雅各布学院在加州大学圣地亚哥分校）

研究人员使用三维打印技术复制板，这将被附连到聚合物以模拟肌肉的结构。这样做的目的是要建立一个机械臂综合软硬材料（不像许多其他的机器人项目，研究人员说倾向于支持一个或其他）。通过创建类似于海马的尾部手臂，研究人员认为手臂将能够掌握不同大小的物体，而不是像一个机器人触手。怎么会这样一只手臂被使用？医疗设备，探索海洋和拆弹都是潜在的用途，研究人员说。

护甲是不是海马的唯一有趣的事情，鱼类含有54种已知属（海马）。他们是什么的动物群的古玩店。 “海马的独特之处在于他们有一个头似马，长管状的鼻子像食蚁兽，一个适于抓握的尾巴像一只猴子，一个育雏袋像袋鼠，迷彩皮肤像比目鱼，和眼睛的独立移动像变色龙“工程的雅各布学院在加州大学圣迭戈，研究发生的迈克尔·波特说。 “我们研究了适于抓握的尾巴，因为[的of对于他们的研究，该小组研究了常见的海马，管海马

该团队的研究成果发表在杂志ACTA Biomaterialia。你可以看到一个视频显示的模拟滑板的原型在下面的视频