PNEUmorph: a shape-morphing interface comprising a pneumatic membrane constrained by variable-length tendons

Abstract

Soft shape-morphing technologies are explored in fields such as soft robotics, metamaterials and design, enabling systems to adapt dynamically through elastic deformations. Applied in mobile devices, actuators, interactive objects and environments, these systems can respond to functional needs and environmental stimuli, communicating information and enhancing human experiences. A primary design goal for these systems is achieving extensive and complex shape transformations. Traditionally, soft robotics employs a pneumatic active layer constrained by a passive layer, limiting the deformation range. However, using dual active layers can expand deformation potential. Expanding on these principles, this work introduces PNEUmorph: a pneumatic surface constrained by a network of variable-length tendons, allowing broader shape transformations than traditional single-layer systems. PNEUmorph’s dual-layer actuation overcomes fixed deformation limits, significantly enhancing shape-morphing capabilities. This paper presents PNEUmorph’s design and geometrical characterization, achieved through an interdisciplinary approach that merges design and soft robotics methods. This study details methods for simulation, fabrication, operation and evaluation, offering insights into experimental results and directions for advancing surface-based soft shape-morphing systems.