Photo-electric dual-driven melamine sponge-based shape memory composite material

Abstract

The development of intelligent materials is a prominent research focus today. Shape memory polymers (SMPs), an emerging category of intelligent materials, exhibit characteristics including low density, easy deformability, a broad temperature range, and facile processability. In this paper, a photo-electro dual-driven shape memory composite material was prepared. Using carbonized melamine sponge (CMS) as the matrix, CMS/CuS was prepared by depositing copper sulfide (CuS) via chemical deposition, and then compounded with ethylene-vinyl acetate copolymer (EVA) to obtain a composite material with both photothermal and electrothermal conversion properties. The introduced copper sulfide nanoparticles exhibit excellent electrical conductivity; notably, as the CuS content increases, the electrical conductivity of the composite material improves significantly. At 0.75 wt% CuS concentration, the composite material stabilizes at 80°C under 3 V and recovers its shape completely within 15 s. The composite material reaches a saturated temperature of 133°C under laser irradiation (0.6 W/cm²), and the shape recovery rate reaches 100% within 30 s. Traditional single-functional shape memory materials can only respond to one type of external stimulus (e.g., thermal stimulation alone or light stimulation alone), and their applications are thus restricted by the availability of specific stimuli. As a multi-driven shape memory composite material, it can address the dilemma of the single functionality of such traditional materials and further meet the operational needs in some complex environments.