The rapid expansion of soft robots and smart electronic devices is driving demand for materials that can not only move and adapt, but also complete their missions without leaving behind unwanted traces. As these technologies are increasingly explored for health care, environmental monitoring, infrastructure inspection, and security applications, robots and devices are expected to operate in places where human access is limited—such as narrow pipes, sealed spaces, underground facilities, and hazardous environments.The rapid expansion of soft robots and smart electronic devices is driving demand for materials that can not only move and adapt, but also complete their missions without leaving behind unwanted traces. As these technologies are increasingly explored for health care, environmental monitoring, infrastructure inspection, and security applications, robots and devices are expected to operate in places where human access is limited—such as narrow pipes, sealed spaces, underground facilities, and hazardous environments.[#item_full_content]