Bio-Inspired High-Low Toughness Multilayer Mechanoluminescent Composite With Superior Mechanical Properties

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Polydimethylsiloxane (PDMS) is crucial for flexible mechanoluminescence (ML) materials, providing stretchability and self-charging properties.
• However, PDMS's inherent low toughness and crack resistance limit the practical application of ML devices.
• Developing robust and high-performance ML materials remains a significant challenge.

Purpose of the Study:

• To enhance the toughness, stretchability, and mechanical stability of PDMS-based ML composites.
• To investigate a biomimetic multilayer architecture for improved material performance.
• To advance the practical applications of flexible ML devices.

Main Methods:

• A multilayer architecture was created by introducing high-toughness silicone-rubber layers into a ZnS:Cu@Al2O3/PDMS matrix.
• This design mimics the hinged microstructure of a clam shell.
• The mechanical and mechanoluminescence properties of the modified composite were evaluated.

Main Results:

• The fracture strain of the modified composite increased from ~100% to 500%, demonstrating significantly enhanced stretchability.
• Mechanoluminescence intensity saw a four-fold boost, coupled with sustained durability over 30,000 cycles.
• Material toughness increased from 0.95 to 4.93 MJ/m³, due to reduced layer thickness and suppressed crack propagation.

Conclusions:

• The biomimetic multilayer strategy effectively enhances the performance of PDMS-based flexible ML composites.
• This approach overcomes the limitations of low toughness and crack resistance in PDMS.
• The findings pave the way for practical applications in stress visualization, intelligent displays, and sensors.