Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, 94305, USA.
Carl Von Ossietzky Universität Oldenburg, 26129, Oldenburg, Germany.
Sci Rep. 2021 Feb 12;11(1):3773. doi: 10.1038/s41598-021-83303-z.
Collective behaviour in flocks, crowds, and swarms occurs throughout the biological world. Animal groups are generally assumed to be evolutionarily adapted to robustly achieve particular functions, so there is widespread interest in exploiting collective behaviour for bio-inspired engineering. However, this requires understanding the precise properties and function of groups, which remains a challenge. Here, we demonstrate that collective groups can be described in a thermodynamic framework. We define an appropriate set of state variables and extract an equation of state for laboratory midge swarms. We then drive swarms through "thermodynamic" cycles via external stimuli, and show that our equation of state holds throughout. Our findings demonstrate a new way of precisely quantifying the nature of collective groups and provide a cornerstone for potential future engineering design.
群体中的集体行为在整个生物世界中都有发生。动物群体通常被认为是进化适应的，能够强大地实现特定功能，因此人们广泛关注利用集体行为进行仿生工程。然而，这需要了解群体的确切性质和功能，这仍然是一个挑战。在这里，我们证明了可以在热力学框架内描述集体群体。我们定义了一组适当的状态变量，并为实验室摇蚊群体提取了状态方程。然后，我们通过外部刺激使群体经历“热力学”循环，并表明我们的状态方程在整个过程中都成立。我们的发现展示了一种精确量化集体群体性质的新方法，并为未来的潜在工程设计提供了基石。
