Giant photostriction rate for remote opto-ultrasonic structural health monitoring.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41735311.
- Also identified by DOI 10.1038/s41467-026-69906-y and PMC identifier 13043965.
- Licence recorded as CC BY-NC-ND.
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Abstract
Extending photocarrier lifetime, accelerating photostrictive strain buildup, and engaging more light-lattice interactions are essential to increase the bulk photostriction rate-a key figure of merit integrating strain magnitude and generation speed (typically < 10<sup>-3</sup> s<sup>-1</sup> in bulk ferroelectrics)-for efficient remote ultrasound generation. Here, we report non-poled terbium-doped (K,Na)NbO<sub>3</sub> ceramics, where Tb<sup>3+</sup> 4f-electron trapping prolongs photocarrier lifetime, enabling efficient carrier drift to domain walls for screening depolarization field. Hierarchical nanostructures-dense nanodomains (accelerating photostriction via coupled local bulk photovoltaic and converse piezoelectric effects) and subwavelength grains (more light-lattice interactions and enhancing collective photostriction)-yield an outstanding bulk photostriction rate of 6.41×10<sup>-1</sup> s<sup>-1</sup>, two orders above conventional bulk ferroelectrics. Non-poled ceramics avoid depoling issue, enabling robust and low power opto-ultrasonic transducers for reliable remote structural health monitoring. Our bulk ferroelectric design strategy enables cost-effective, high-performance opto-ultrasonic sensing technologies.