Multifunctional mandibles of ants: Variation in gripping behavior facilitated by specific microstructures and kinematics
Multifunctional mandibles of ants: Variation in gripping behavior facilitated by specific microstructures and kinematics
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蚂蚁的多功能下颌：特定的微观结构和运动学促进了抓握行为的变化
DOI：
10.1016/j.jinsphys.2019.103993
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发表时间：
2020
影响因子：
2.2
通讯作者：
Zhigang Wu
中科院分区：
文献类型：
--
作者：
Wei Zhang;Minghao Li;Guobin Zhang;Zijin Guan;Jianing Wu;Zhigang Wu
某些蚂蚁物种的细长下颌是灵巧的抓手，可以输出各种任务所需的各种力量。我们的实验和理论相结合的研究揭示了Harpegnathos venator下颌的多功能，这是由特定的微结构和特征运动学促进的。首先，我们发现H.venator可以通过关闭长长的下巴来拉下蜘蛛(异足动物)的腿。我们观察到，蚂蚁通常用其下颌的远端或中部夹住蜘蛛的腿。相比之下，蚂蚁可以用下巴的近端夹住卵子，而不会造成损害。我们的结果表明，蜘蛛的腿总是在髋关节-粗隆关节处骨折。其次，我们发现，折断蜘蛛腿所需的力量可以达到蚂蚁体重的500倍。另一方面，抓取鸡蛋时，最大力可以控制在2×10-6N以下。通过结合显微结构成像、运动学跟踪和数学建模，我们发现下颌内侧锋利的牙齿和密集的刷毛决定了高粘附力，而下颌的凹齿和双向旋转有利于温和的抓取。我们通过构建一个人工下颌对来验证我们的发现。这项工作扩展了对蚂蚁下颌生理多功能的认识，并应用力学分析工具和相关实验装置为揭示昆虫附肢的多功能提供了新的途径。
The elongated mandibles of certain ant species are dexterous grippers that can output a wide range of forces as needed for various tasks. Our combined experimental and theoretical research reveals the multifunctionality of the mandibles of Harpegnathos venator that is facilitated by specific microstructures and characteristic kinematics. First, we found that H. venator can pull off a spider’s (Heteropoda venatoria) leg by closing its long mandibles. We observed that the ant usually clamps the spider’s leg using the distal or middle part of its mandibles. In contrast, the ant can grip its egg with the proximal parts of its mandibles without causing damage. Our results showed that the spider’s legs are always fractured at the coxa-trochanteral joint. Second, we found that the force required to fracture the spider’s leg can be up to 500 times the ant’s body weight. On the other hand, the maximum force can be controlled to less than 2× 1 0-6 N while gripping an egg. By combining microstructure imaging, kinematic tracking and mathematical modeling, we uncovered that the sharp teeth and dense bristles on the internal side of the mandibles determine the high adhesion force, while the concave teeth and biaxial rotation of the mandibles facilitate gentle gripping. We validated our findings by constructing an artificial mandible pair. This work expands the knowledge of the physiological multifunctionality in ant mandibles, and provides novel ways to reveal the multifunctionality in insect appendages by applying the tools of mechanical analysis and related experimental devices.