Bat-wing-inspired lattice metamaterials for broadband vibration isolation: Design, optimization, and experimental validation

This study proposes a novel class of bio-inspired two-dimensional lattice metamaterials derived from the geometric architecture of a bat wing for broadband vibration isolation. Seven structural variants-including sinusoidal and concave-rib configurations are developed to examine the influence of curved-ligament morphology on phononic bandgap formation. Dispersion relations are computed using finite-element analysis with Bloch boundary conditions, and the results reveal that Bragg scattering dominates bandgap generation, while localized resonant modes contribute to additional narrow gaps at lower frequencies. To efficiently explore the high-dimensional design space, a hybrid genetic-algorithm and artificial-neural-network (GA–ANN) approach is employed, reducing computational time by nearly one order of magnitude. Multi-objective optimization is conducted to maximize total bandgap coverage, maximize the first bandgap width, and minimize its onset frequency, supported by Pareto-front and TOPSIS analysis. The sinusoidal configuration achieves the largest cumulative bandgap (70.8% within 0–5 kHz), whereas the baseline bat-wing design provides the widest continuous bandgap (66.3%). Experimental testing on 3D-printed specimens validates the numerical predictions for both in-plane and out-of-plane wave propagation. The results demonstrate that bio-inspired curved-rib lattice designs offer an effective route for tunable and broadband vibration isolation in mechanical systems.