Elastic Gridshell Display

Abstract

3D shape-morphing devices possess incredible potential as expressive physical interfaces for design exploration, augmented-reality, and robotics. However, current solutions typically require numerous actuators and remain limited in shape diversity, constraining practical applications. We present a shape-changing interface using an actuated elastic gridshell capable of automatically reconfiguring between complex curved geometries.

Elastic gridshells are connected grids of elastic rods that can approximate curved surfaces through out-of-plane bending. Although gridshells are often created as geometrically interesting deployable structures, existing design and control methods limit the set of possible shapes to pre-determined static configurations, restricting reconfigurability. In this paper, we introduce a novel framework for a reconfigurable and expressive robotic elastic gridshell. Our framework consists of three core components: (1) a novel robotic design with sparse boundary actuation to enable 3D shape-change; (2) a physics-based simulator, predicting the dynamics of the device given a sequence of actuation inputs; and (3) a trajectory optimization pipeline computing feasible control inputs that transform the gridshell from an initial configuration to a target geometry. The pipeline first generates valid control paths using sampling-based planning, then solves a bi-level optimization problem to refine shape matching. We validate our approach through motion tracking, demonstrating that our system can programmatically produce a wide variety of shapes with high local curvature and interesting geometry.