Stretchable Biaxial and Shear Strain Sensors Using Diffractive Structural Colors.

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Dynamic structural colors using plasmonic nanostructures or photonic crystals are key for stretchable sensors.
• Existing strain-responsive color techniques lack exploration in sensing mechanisms, stability, and reproducibility.

Purpose of the Study:

• To introduce a stretchable, diffractive, color-based wireless strain sensor.
• To demonstrate strain measurement across the entire visible spectrum using tunable diffractive colors.

Main Methods:

• Fabrication of a stretchable sensor with cone-shaped nanostructures on an elastomeric substrate.
• Tuning diffractive color by altering grating pitch through substrate stretching/compression.
• Designing and evaluating three strain-sensing modes: large-deformation tensile, biaxial 2D, and shear strain.

Main Results:

• Successful fabrication of the proposed strain sensor.
• Demonstration of color tuning based on grating pitch changes.
• Validation of applicability for large-deformation (up to 100%) tensile, biaxial 2D, and shear (up to 78%) strain sensing.

Conclusions:

• The developed sensor provides a novel approach for wireless strain measurement using visible spectrum color changes.
• The method shows potential for various strain-sensing applications requiring high deformability and different strain types.