Motivated by the need for sustainable aviation, this doctoral thesis explored how the concept of actuated adaptive wingtips could enhance aircraft efficiency and performance. Actuated adaptive wingtips can fold during ground operations or specific flight scenarios by integrating a multifunctional hinge at the outboard section of high-aspect-ratio wings. The concept of actuated adaptive wingtips expands the potential operating modes of folding wingtips (FWTs) beyond the current state-of-the-art, enabling extended load alleviation, mission adaptability, advanced flight control, or active flutter suppression. The overall thesis aim was to advance this concept by designing and characterizing a wingtip actuator based on the technological approach of pressure-actuated cellular structures (PACS). Inspired by the nastic movements of plants, PACS can bend in two opposite directions and adjust their structural stiffness by varying their cell pressurization. This section summarizes the thesis’s main contributions and outlines an overall design approach incorporating these findings.