Skin-inspired self-healing polycaprolactone-based composite induced by photo/electro stimuli for highly absorbed and stable electromagnetic interference shielding

The endeavor to attain prolonged stability and heightened electromagnetic interference shielding effectiveness (EMI SE) in polymer-matrix composites remains an arduous pursuit, particularly when subjected to external mechanical trauma or adverse environmental conditions. In this context, a self-healing and efficient EMI shielding polycaprolactone (PCL) composite with a unique electromagnetic gradient and interface-metalized segregated structure is assembled through layer-by-layer casting and a hot-pressing process. The combined effect of the induction of the electromagnetic gradient layer and the massive multiple interface reflection and scattering from the segregated-like structure results in an exceptional EMI SE of 57.0 dB and a low reflection (R) value of only 0.28. Additionally, the composite boasts impressive photothermal and electrothermal properties, allowing for self-healing under solar irradiation or electrical stimulation. Remarkably, this self-healing capability has been demonstrated through five cutting and healing cycles, exhibiting an impressive EMI SE retention rate of 88%. Consequently, the composite with rapid photo/electro-driven self-healing properties will be able to maintain EMI shielding performance.