Strain sensor based on a flexible frequency-selective surface with temperature compensation.

Area of Science:

• Materials Science
• Electrical Engineering
• Sensor Technology

Background:

• Developing accurate and robust strain sensors for complex environments is crucial.
• Existing sensors often suffer from cross-sensitivity to temperature, limiting their application.
• Frequency-Selective Surfaces (FSS) offer potential for novel sensor designs.

Purpose of the Study:

• To design and fabricate a biaxial strain sensor utilizing a flexible Frequency-Selective Surface (FSS).
• To achieve independent strain detection in two dimensions with minimal temperature cross-sensitivity.
• To evaluate the sensor's performance in terms of strain sensitivity and temperature drift.

Main Methods:

• Fabrication of the FSS sensor using photolithography, wet etching, and laser cutting on a flexible polymer substrate.
• Testing the sensor's resonant frequency response under varying temperatures (20-100°C).
• Conducting tensile tests to evaluate the linear elastic relationship and sensitivity to strain.

Main Results:

• The FSS sensor demonstrated a low relative resonant frequency change of 0.46% over a 20-100°C temperature range.
• A linear elastic relationship between stress and strain was observed up to 66.6% strain.
• High strain sensitivity of 700 MHz/mm was achieved for tensile displacements between 0.5-3 mm.

Conclusions:

• The developed FSS sensor exhibits high strain sensitivity and excellent resistance to temperature drift.
• The sensor's ability to independently detect biaxial strain makes it suitable for demanding applications.
• This flexible FSS sensor holds significant practical value for strain monitoring in diverse and challenging environments.