Abstract
Smart adaptable multistable (SAM) building façades offer a promising strategy for improving building performance by passively responding to environmental stimuli while maintaining mechanical stability and low energy demand. This study investigates a scalable multistable façade module based on the nonlinear snap-through behavior of compliant curved-beam mechanisms. The proposed module achieves three distinct and repeatable geometric states, including an initial configuration and two stable post–snap-through states. Prototypes were fabricated using fused deposition modeling of flexible polylactic acid and experimentally characterized under quasi-static in-plane loading. A systematic parametric study quantified the influence of four key geometric parameters on snap-through behavior and actuation demand. Increasing the number of bistable beams from one to two raised the first snap-through force by 150%, establishing robust multistability, whereas further increasing the bistable beam count to three resulted in marginal gains of less than 8% in the first snap-through force. Bistable beam spacing showed a non-monotonic effect on snap-through force, with the 6 mm configuration yielding the highest force response, exceeding the 4mm and 7mm cases by up to 64.7% and 58.3%, respectively. Reducing the edge distance from 30mm to an intermediate value of 25mm decreased the first and second snap-through forces by 22% and 26%, respectively. Similarly, a pulling-element thickness of 0.4mm resulted in the lowest actuation force of 18.72N, reducing the first snap-through force by 16% and 20.9% compared to the 0.3mm and 0.5mm configurations, respectively. Overall, the results demonstrate that geometric tuning directly controls snap-through behavior, with intermediate parameter values minimizing actuation force while preserving robust multistability. These findings support the feasibility of scalable, low-energy multistable façade systems.