Multi-physics property evaluation and actuation response of first-order fractal-inspired photostrictive composites: a finite element analysis

A photostrictive actuator helps the smart structure to be actuated wirelessly. Researchers are attempting to enhance its actuation response. This research article explores first-order fractal-inspired photostrictive 3–3 composites to enhance the actuation response of photostrictive actuators. The proposed structure has been considered and designed for enhanced multifunctional actuation. This configuration consists of piezoelectric PMN-35PT reinforcements and photovoltaic PTB7-Th as a matrix, enabling opto-electro-mechanical coupling. All effective material properties were evaluated using a representative volume element (RVE) approach for fiber aspect ratios (L/D = 2, 2.5, 3). Actuation performance was analyzed under 60 mW/cm² light irradiation using the finite element method. Maximum deflections for the cantilever beam decreased from −3.77 × 10⁻³ m (L/D = 2) to −1.45 × 10⁻³ m (L/D = 3), the simply supported beam 4.71 × 10⁻⁴ m (L/D = 2) to 1.81 × 10⁻⁴ m (L/D = 3), and clamped square plate shows 1.6 × 10⁻⁴ m (L/D = 2) demonstrating the tunability of actuation response. To the best of our knowledge, this is the first demonstration of a photostrictive actuator based on a first-order fractal-inspired composites, modelled via fully-coupled multiphysics finite-element framework. This study highlights the potential of fractal-inspired photostrictive composites for applications in aerospace, robotics, and MEMS, where adaptive material performance is crucial.