Method for preparing micro-nano-particle-reinforced PDMS-based FGM using 3D printing single nozzle

A single nozzle forming micro-nano-particle-reinforced polydimethylsiloxane (PDMS)-based functionally gradient material (FGM) was prepared by 3D printing. In the experiment, SiC and SiO2 particles were selected as the reinforcing phase, and an FGM with a volume fraction increasing from 0% to 20% layer by layer was prepared. The prepared FGM has no pores, shows good interlayer bonding, and contains micro-nano-particles evenly distributed in the layer without agglomeration. The mechanical properties and thermal conductivity of the PDMS-based FGM reinforced by SiC particles changed layer by layer. When the volume fraction of SiC particles reached 20%, the tensile modulus and hardness increased by 83% and 36%, respectively, and the thermal conductivity increased by 21%. SiO2-particle-reinforced PDMS-based FGMs have a lower layer-by-layer elongation rate after fracture than SiC particle-reinforced PDMS-based FGMs. The preparation of the above materials satisfies the actual demand for substrate materials in the field of flexible electronic products. While maintaining flexibility, high reinforced particle content can fully provide protection or heat dissipation for embedded electronic devices. (C) 2020 Elsevier B.V. All rights reserved.