Epoxy microlattice with simultaneous self-sensing and electromagnetic interference shielding performance by in-situ additive manufacturing

The development of epoxy nanocomposite architectures capable of self-sensing the internal structural response to mechanical stimuli and exhibiting multifunctionality represents a significant challenge to the scientific community. Here, an in-situ additive manufacturing technique is developed to construct robust SiO₂/epoxy host material and piezoresistive nanocarbon/epoxy sensing elements into an engineered 3D microlattice. The integration of microscale sensing elements with tailored embedment locations and contents enables the real-time detection of in-situ strain under varying loadings, without compromising the mechanical properties of the original host structure. Additionally, the epoxy microlattices containing 3D interconnected network of sensing elements present excellent electromagnetic interference shielding properties, attaining a high shielding effectiveness of up to 33 dB. Furthermore, the applications of the epoxy microlattice in defect-recognizable composite lattices and multifunctional protective devices are demonstrated. The present findings suggest an effective strategy for the development of intrinsically smart epoxy nanocomposites with customized microstructure and unprecedented multifunctionality.