Near-infrared stress memory emitters enable delayed impact visualization in illuminated environments

Area of Science:

• Materials Science
• Optoelectronics
• Solid State Physics

Background:

• Conventional mechanical detection methods, often camera-based, are slow and prone to errors due to complex image analysis.
• There is a need for rapid, accurate, and visualized mechanical detection systems suitable for ambient environments.

Purpose of the Study:

• To introduce a new class of near-infrared stress memory emitters for efficient mechanical detection.
• To demonstrate the capability of these emitters for real-time visualization and capture of mechanical impacts.

Main Methods:

• Development of Ca(Sr)ZnOS:Yb3+/Pb2+ crystals with engineered sub-bandgap states.
• Utilizing combinatorial engineering and isostructural host blending for persistent mechanoluminescence.
• Employing ultraviolet charging to modulate luminescence intensity and duration for data capture.

Main Results:

• Achieved persistent mechanoluminescence at 981 nm with high brightness (up to 11 × 10^7 photons/event) and durability (up to 100 s).
• Demonstrated direct capture and visualization of ball impacts with a short processing time (0.39 s) and high accuracy.
• Successfully modulated luminescence properties through material composition and UV charging.

Conclusions:

• The developed persistent mechanoluminescent crystals offer a promising alternative to conventional detection methods.
• These materials enable fast, visualized mechanical detection with broad applications in stress sensing and human-machine interfaces.
• The engineered optical materials open new avenues in mechano-opto-electronic devices.