Skin wrinkles and folds enable asymmetric stretch in the elephant trunk.
Skin wrinkles and folds enable asymmetric stretch in the elephant trunk.
复制标题
皮肤皱纹和褶皱使大象的鼻子不对称地伸展。
DOI：
10.1073/pnas.2122563119
复制
发表时间：
2022-08-02
影响因子：
11.1
通讯作者：
中科院分区：
文献类型：
--
作者：
像章鱼臂和象鼻这样的肌肉型水生动物因其在抓取各种物体时的灵活性而备受关注。这些动物激发了软机器人操纵器和执行器的各种应用，从与人类一起救灾到采摘水果。对于软机器人施加大的力，他们将需要一个保护皮肤。这项工作表明，皮肤中的皱纹和褶皱可以为柔软的附属物提供保护和灵活性。我们希望这项工作将激励未来的工作在皮肤力学在动物和机器人。大象的鼻子是多功能的：它必须是灵活的包裹植被，但坚韧的撞倒树木和抵御攻击。一个附肢怎么能同时满足这两个约束呢？在这项实验和理论相结合的研究中，我们挑战非洲象，让它们的象鼻只能水平延伸到远处的物体。令人惊讶的是，躯干并不均匀地延伸，而是表现出一个背侧“关节”，比相应的腹侧部分多伸展15%。使用材料测试与皮肤的大象尸体，我们表明，不对称的部分原因是由于皮肤的模式。背部皮肤是折叠的，比腹部皮肤多15%的柔韧性。皮肤褶皱保护背部，并拉伸以便于向下包裹，这是拾取物品时最常见的抓握方式。大象的皮肤也足够坚硬，足以影响其力学：在关节处，皮肤需要比相应长度的肌肉多13倍的能量来拉伸。使用褶皱和折叠来调节刚度可以为生物学和软机器人技术提供有价值的概念。
Muscular hydrostats such as octopus arms and the elephant trunk have received much attention because of their dexterity in grabbing a wide range of objects. These animals have inspired soft-robotic manipulators and actuators with various applications, from working with humans in disaster relief to picking up fruit. For soft robots to apply large forces, they will need a protective skin. This work shows that wrinkles and folds in skin can provide protection and flexibility to soft appendages. We hope this work will inspire future work in the mechanics of skin in both animals and robots. The elephant’s trunk is multifunctional: It must be flexible to wrap around vegetation, but tough to knock down trees and resist attack. How can one appendage satisfy both constraints? In this combined experimental and theoretical study, we challenged African elephants to reach far-away objects with only horizontal extensions of their trunk. Surprisingly, the trunk does not extend uniformly, but instead exhibits a dorsal “joint” that stretches 15% more than the corresponding ventral section. Using material testing with the skin of a deceased elephant, we show that the asymmetry is due in part to patterns of the skin. The dorsal skin is folded and 15% more pliable than the wrinkled ventral skin. Skin folds protect the dorsal section and stretch to facilitate downward wrapping, the most common gripping style when picking up items. The elephant’s skin is also sufficiently stiff to influence its mechanics: At the joint, the skin requires 13 times more energy to stretch than the corresponding length of muscle. The use of wrinkles and folds to modulate stiffness may provide a valuable concept for both biology and soft robotics.
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影响因子：
2.4
作者：
LANIR, Y;FUNG, YC
通讯作者：
FUNG, YC
DOI：
10.1111/j.1096-3642.1985.tb01178.x
发表时间：
1985-01-01
影响因子：
2.8
作者：
KIER, WM;SMITH, KK
通讯作者：
SMITH, KK
影响因子：
1.5
作者：
Anderson, Christopher V.;Sheridan, Thomas;Deban, Stephen M.
通讯作者：
Deban, Stephen M.
影响因子：
3.9
作者：
Marvi, Hamidreza;Bridges, Jacob;Hu, David L.
通讯作者：
Hu, David L.
DOI：
10.1109/tbme.2009.2033464
发表时间：
2010-04
期刊：
IEEE transactions on bio-medical engineering
影响因子：
--
作者：
Liang X;Boppart SA
通讯作者：
Boppart SA