Novel photostrictive 0-3 composites: A finite element analysis

Simultaneous action of photovoltaic effect and converse piezoelectric effect will induce the photostrictive effect. In contrast to the naturally occurring photostrictive material, the present study proposes a 0-3 photostrictive composite. The current photostrictive composite comprises of poly{4,8-bis[5-(2-ethyl-hexyl) thiophen-2-yl] benzo[1,2-b:4,5-b′] dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethyl-hexyl) carbonyl] thieno[3,4-b] thiophene-4,6-diyl} (PTB7-Th) as organic photovoltaic polymer matrix and Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 (PMN-35PT) as the particulates. The current study shows that the present 0-3 photostrictive composite is a suitable alternative for the most popular lead-based photostrictive material. While evaluating all the effective elastic, dielectric, piezoelectric, and pyroelectric properties of 0-3 photostrictive composite, the effect of local fluctuations was incorporated in representative volume element (RVE) using the finite element method. A finite element formulation using a degenerated shell element is derived to simulate the actuation response of the proposed 0-3 photostrictive composite. Numerical studies have been performed on cantilever and simply supported beams. The maximum tip and center deflection of cantilever beam and simply supported beam bonded with 0-3 photostrictive patch is 9.75×10−4 mm and 1.22×10−4 mm, respectively. The maximum value of the effective piezoelectric coefficient d31eff, effective thermal expansion coefficient αeff, effective Young’s modulus E1eff, and effective pyroelectric coefficient peff of proposed 0-3 photostrictive composite are −3.81×10−13 m/V, 4.59×10−4 °C−1, 1.63×109 N/m2, and 7.57×10−5 C/m2 K, respectively, obtained at 25% volume fraction of particulates. This study opens possibilities of photostrictive coupling in composites.