Rate-dependent adhesion in combination with the collaborative action of limbs facilitates grasshoppers’ reliable attachment under highly dynamic conditions

Dynamic attachment is essential for animals to cope with unexpected disturbances. Minor attention has been paid to the dynamic performance of the individual adhesive pads. However, the whole-animal results are even more informative for understanding animal attachment intelligence. In this article, we tested grasshoppers by pulling them off at different speeds on a glass rod. Surprisingly, the feet did not always maintain contact with the rod but released when the legs were extended and tried to reconnect rapidly with the surface. This type of adjustment may effectively reduce the impact on the pads and their potential damage. As we increased the pulling speeds from 1 mm/s to 400 mm/s, the maximum forces of insects with a single front tarsus and insects with entire tarsi were almost proportional to the 1/3 power of pulling speeds by 0.11 times and 0.29 times, respectively. In extreme cases, the force was even 800 times greater than the weight of the insects, which is an extremely high performance for the smooth insect pads. This work not only helps us to understand the dynamic attachment of the animal as a whole but also enriches our knowledge of animal attachment in extreme situations.

动态附着对于动物应对突发干扰至关重要。对于个体粘附垫的动态性能，关注尚显不足。然而，整只动物的实验结果对于理解动物的附着智能更为启迪。在本研究中，我们通过对蝗虫在不同速度下沿玻璃棒拉扯的实验，对其进行了测试。令人惊讶的是，当腿伸展并试图迅速重新附着于表面时，足部并不总是与棒保持接触，而是在此过程中释放。此类调整或许能有效减轻垫子的冲击及其潜在损害。随着拉扯速度从1毫米/秒增至400毫米/秒，单前足节昆虫和整足昆虫的最大力量分别与拉扯速度的1/3次幂成正比，分别为0.11倍和0.29倍。在极端情况下，力量甚至高达昆虫体重的800倍，这对于光滑的昆虫足垫而言是一项极为卓越的性能。本研究不仅有助于我们理解动物整体的动态附着能力，同时也丰富了我们在极端情况下对动物附着机制的认识。