Department of Engineering Mechanics, College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China.
Department of Engineering Mechanics, College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China.
J Mech Behav Biomed Mater. 2018 Oct;86:345-351. doi: 10.1016/j.jmbbm.2018.07.001. Epub 2018 Jul 2.
With the evolution for several millions of years, leeches have developed a perfect capability to resist mechanical loads, which provides many inspirations to engineer new materials and new devices. To uncover the mechanism of its strong survival ability, several mechanical approaches, such as compression, tension, adhesion, impact and blood suction experiments were tried. Our experimental results show that a leech (Hirudo nipponia) can surprisingly withstand a compressive force of nearly 10 times its body weight. In tension, this animal demonstrates large deformation and its strain can reach a value bigger than 3. To avoid being removed from the host skin, it produces an adhesion force superior to 118 times its body weight, and it can endure an impact force at least 1500 times its weight. Also the leech skin can bear an internal fluid pressure of around 6 times the atmospheric pressure. These data show that the leech cannot be killed easily through normal mechanical loading approaches. All these amazing performances lie in hierarchical structures and ductility of the skin with highly developed and compact annuluses, and this feature is beneficial to leech's survival.
经过几百万年的进化，水蛭已经发展出了完美的抗机械载荷能力，这为工程师设计新材料和新设备提供了许多启示。为了揭示其强大生存能力的机制，人们尝试了几种机械方法，如压缩、拉伸、粘附、冲击和吸血实验。我们的实验结果表明，一条水蛭（日本医蛭）可以承受近 10 倍于其体重的压缩力。在拉伸时，这种动物会发生很大的变形，其应变可以达到 3 以上的值。为了避免从宿主皮肤上脱落，它产生的粘附力超过其体重的 118 倍，并且可以承受至少 1500 倍于其重量的冲击力。此外，水蛭的皮肤可以承受约 6 倍大气压的内部流体压力。这些数据表明，通过正常的机械加载方法，水蛭不容易被杀死。所有这些惊人的性能都取决于皮肤的分层结构和延展性，以及高度发达和紧凑的环状结构，这一特征有利于水蛭的生存。
