Ultrasensitive and Stretchable Strain Sensors Based on Laser-Induced Graphene With ZnO Nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Laser-induced graphene (LIG) is promising for flexible/stretchable sensors but has limited sensitivity.
• Enhancing LIG strain-sensing sensitivity requires material and structural improvements.

Purpose of the Study:

• To significantly improve the sensitivity of LIG-based strain sensors.
• To explore ZnO nanoparticle-assisted photothermal enhancement for LIG fabrication.
• To develop multifunctional sensor sheets for wearable applications.

Main Methods:

• Fabrication of LIG using ZnO nanoparticle-assisted photothermal enhancement.
• Transferring LIG from polyimide (PI) to poly(dimethylsiloxane) (PDMS).
• Integration of strain and ultraviolet (UV) sensors onto a flexible sheet.

Main Results:

• Achieved ultrahigh sensitivity in stretchable strain sensors with a gauge factor of 1214 at 10% strain (60x higher than without ZnO NPs).
• Demonstrated selective graphenization enabled by ZnO NPs, reducing the conversion threshold fluence.
• Successfully created a dual-sided sensor sheet for simultaneous UV intensity and joint bending angle monitoring.

Conclusions:

• ZnO NP-assisted photothermal enhancement substantially boosts LIG strain sensor sensitivity.
• The developed method enables highly sensitive and stable multifunctional sensors for wearable devices.
• This approach holds significant potential for advanced sensor applications requiring high performance and stability.