Between Control and Surrender:Exploring Shape and Interactivity with Human-Scale Inflatable Robots

Human-scale inflatable robots that respond to users’ movements offer a unique opportunity to explore embodied and relational interaction. Yet, little is known about how their form and interactive behaviour shape engagement and perception. This study presents three inflatable robots designed to explore different levels of user control: Barrel affords high user freedom, allowing approach or retreat; Chair introduces partial constraint through a semi-enclosing structure; Jacket envelops the user, with movement largely determined by the robot. Across all systems, robot motion responds to user behaviour in semi-random ways, contributing to a sense of agency. Participants engaged through a think-aloud protocol, followed by semi-structured interviews and a drawing activity. Findings show that, in the absence of clear prior models, participants actively constructed interpretations of behaviour, attributing agency and intention, while variations in control shaped trust and relational dynamics. These results offer insights for designing human-scale soft robots that support rich, embodied interaction.