Decoupling and <i>De Novo</i> Design of Flexible Polymeric Films for High‐Temperature Triboelectric Sensing and Electromagnetic Shielding

Abstract

ABSTRACT Polymer‐based triboelectric nanogenerators (TENGs) are shining in fields of micro‐energy harvesting and active sensing by virtue of their flexibility and processability. However, thermionic emission and thermal deformation reduce triboelectric output and distort sensing signals, thereby limiting practical applications in high‐temperature environments. Herein, the charge generation and collection units of polymeric TENGs are decoupled for separate de novo design. A dipolar glass polymer, cardo poly(aryl ether) (CPAE), is synthesized with alternating pendant and main‐chain dipoles and bulky, rigid cardo substituent. Aromatic polyphenol‐anchored MXene nanosheets are subsequently crosslinked and sandwiched within thermostable CPAE films, which improves resistance to high‐temperature oxidation. Thanks to the interlayer modulation of MXenes, the total and absorption electromagnetic shielding effectiveness of the resulting film rises by 55% and 195% compared to pristine MXene films, respectively. Even after annealing at 250°C for 24 h, the shielding effectiveness decreases by only ∼1.5%. Moreover, the resulting TENG exhibits an unusual heat‐induced triboelectric enhancement, with an output voltage of 472.2 ± 0.9 V and a power density of 2250.6 ± 27.7 mW/m 2 at 250°C, which compares favorably with most reported polymer‐based TENGs. This work provides a novel technical pathway for flexible electromagnetic protection and self‐powered sensing under extreme operating conditions.