Configurable direction sensitivity of skin-mounted microfluidic strain sensor with auxetic metamaterial

Area of Science:

• Materials Science
• Mechanical Engineering
• Sensor Technology

Background:

• Electromechanical coupling is crucial for stretchable strain sensor performance.
• Current methods for regulating this coupling are limited by intrinsic device properties.

Purpose of the Study:

• To present a microfluidic strain sensor with a core-shell package design incorporating auxetic metamaterials (AM).
• To demonstrate how AM can override intrinsic mechanical properties to tune deformation and directional strain sensitivity.

Main Methods:

• Developed a core-shell packaged microfluidic strain sensor.
• Integrated auxetic metamaterials (AM) with varying designs into the sensor package.
• Investigated the effect of AM on microfluidic channel deformation and strain sensitivity.

Main Results:

• Auxetic metamaterials (AM) effectively tuned microfluidic channel deformation and enabled directional strain sensitivity.
• The gauge factor (GF) in the radial direction was tunable from negative to positive values.
• The sensor could be configured as omnidirectional or directional by changing the AM.

Conclusions:

• The AM-integrated microfluidic strain sensor offers a method to precisely control electromechanical coupling and directional sensitivity.
• This technology shows promise for skin-mounted tactile detection with high tolerance to movement artifacts.