As a transparent semiconductor, indium oxide (In₂O₃) exhibits intrinsically low dielectric parameter, rendering it ineffective for microwave absorption. Overcoming its inherent wide bandgap and limited dielectric loss to achieve effective microwave absorption presents a significant challenge. Herein, a lattice defect engineering strategy is proposed to construct oxygen vacancy-rich indium oxide (In₂O_3-x) and carbon-doped indium oxide (In₂O_3-x/C) particles with extrinsic defects. This approach achieves a breakthrough in the effective absorption bandwidth (EAB) of pristine In₂O₃, expanding it from 0 to 3.7 GHz. Furthermore, this study discovers that higher 1,2-benzisothiazoline-3-one dosages increase the oxygen vacancy concentration in In₂O_3-x/C, which is crucial for the material to exhibit microwave absorption capabilities. In particular, the In₂O_3-x/C-0.3 sample demonstrates enhanced microwave absorption through the synergistic effect of carbon doping, achieving a broad EAB of 5.0 GHz. Density Functional Theory calculations further reveal that the introduction of oxygen vacancies and carbon doping can optimize the band structure, reduce the bandgap and induce internal charge redistribution, thereby enhancing the conductive and polarization losses. This research is expected to open up a new avenue in the field of microwave absorption for In₂O₃ applications.

The ionic conductive elastomers show great promise in multifunctional wearable electronics, but they currently suffer from liquid leakage/evaporation or mechanical compliance. Developing ionic conductive elastomers integrating non-volatility, mechanical robustness, superior ionic conductivity, and ultra-stretchability remains urgent and challenging. Here, we developed a healable, robust, and conductive elastomer via impregnating free ionic liquids (ILs) into the ILs-multigrafted poly(urethane-urea) (PUU) elastomer networks. A crucial strategy in the molecular design is that imidazolium cations are largely introduced by double-modification of PUU and centipede-like structures are obtained, which can lock the impregnated ILs through strong ionic interactions. In this system, the PUU matrix contributes outstanding mechanical properties, while the hydrogen bonds and ionic interactions endow the elastomer with self-healing ability, conductivity, as well as non-volatility and transparency. The fabricated ionic conductive elastomers show good conductivity (3.8 × 10⁻⁶ S·cm⁻¹), high mechanical properties, including tensile stress (4.64 MPa), elongation (1470%), and excellent healing ability (repairing efficiency of 90% after healing at room temperature for 12 h). Significantly, the conductive elastomers have excellent antifatigue properties, and demonstrate a highly reproducible response after 1000 uninterrupted extension-release cycles. This work provides a promising strategy to prepare ionic conductive elastomers with excellent mechanical properties and stable sensing capacity, and further promote the development of mechanically adaptable intelligent sensors.