Current research is expanding toward the extremely macroscopic，delving into the extremely microscopic，advancing toward extreme conditions，and making efforts in highly integrated and cross-disciplinary fields，continuously pushing the boundaries of human cognition. Focusing on the development needs of major equipment for exploration in extreme environments from the deep sea，deep space，deep earth，deep cavities，and polar regions named the ‘Four Depths and One Pole’，the forum engaged in in-depth discussions on the basic research of physical intelligent system （PIS）. PISs in extreme environments need to achieve autonomous and collaborative operations under extreme conditions such as ultra-high pressure，large temperature variations，and strong interference. This involves the core content of the collaborative design of materials-structure/mechanism-function of physical intelligent structure；autonomous perception-drive-control-self-healing mechanisms; the foundation of artificial intelligence （AI） models under scarce data conditions; trusted communication and swarm intelligence; and system-level verification in extreme environments. This paper systematically reviews the status，development trends，and challenges of PIS in typical extreme application scenarios. Based on the characteristics of structural mobility，intelligence of the body，intelligent analysis of the environment，and multi-system collaboration，it further distills the key scientific issues of PIS in terms of the tolerance of intelligent structure bodies，the robustness of individual intelligent systems，and the stability of collaborative intelligent systems. This paper also explores the frontier directions of the development of PIS in extreme environments.
Wang et al. (Wed,) studied this question.