Shielding-Sensing Integrated Multilayer PET–Carbon Nanotube Composites for 5G Applications

We designed a shielding–sensing integrated multilayer composite based on PET (poly(ethylene terephthalate)) and carbon nanotubes using UV laser scribing and electroless plating. APTES ((3-aminopropyl)triethoxysilane)-modified carbon nanotubes and the mixture of carbon nanotubes and silica gel were used as the active and shielding layer in the composite, respectively. The electrochemical performance and electromagnetic shielding effectiveness (SE) were investigated to assess the sensing and shielding properties of the composite. Under optimized conditions, the sensor achieved a sensitivity of 6699.0 μA mM–1 cm–2 with a linear range (LR) of 1.0–5 mM at high concentrations toward glucose oxidation. In contrast, a sensitivity of 7140.0 μA mM–1 cm–2 in the linear range of 10–60 μM was displayed for low concentrations. Simultaneously, the composite exhibited a SE value up to 43.64 dB between 30 and 6000 MHz. To explore the protective effect of the designed composite, the electric field distribution was calculated through finite difference time domain (FDTD) simulations. Additionally, tensile tests were conducted to validate the excellent serviceability and stretchability of the composite. The as-prepared multilayer composite with integrated shielding–sensing function holds great potential in the wearable physiology monitoring and electromagnetic interference shielding applications for 5G electronic products.