Consistent Thermal Conductivities of Spring-Like Structured Polydimethylsiloxane Composites under Large Deformation

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Flexible electronics require materials with high and stable thermal conductivity to manage heat.
• Current materials often fail or degrade under mechanical stress, limiting their application.
• Addressing heat accumulation is crucial for the performance and longevity of flexible devices.

Purpose of the Study:

• To develop flexible, thermally conductive materials with consistent performance during large deformations.
• To investigate the use of 3D printed spring-like silver nanowire (S-AgNW) structures within a polymer matrix.
• To enhance heat dissipation in flexible electronic applications.

Main Methods:

• Fabrication of S-AgNW/polydimethylsiloxane (PDMS) composites using 3D printing.
• Characterization of thermal conductivity (λ) under various deformation conditions (elongation, compression, bending).
• Comparison with composites containing randomly dispersed silver nanowires (R-AgNW/PDMS).

Main Results:

• S-AgNW/PDMS composites achieved a thermal conductivity of 7.63 W m⁻¹ K⁻¹ (20 vol% AgNW), significantly higher than PDMS and R-AgNW/PDMS.
• Thermal conductivity variation remained below 2% even under 200% elongation, 50% compression, or 180° bending.
• The heat-transfer coefficient was 1.3 times higher than R-AgNW/PDMS, reducing CPU temperature by 6.8 °C.

Conclusions:

• 3D printed S-AgNW/PDMS composites provide superior and stable thermal conductivity for flexible electronics.
• The spring-like structure effectively accommodates large deformations without compromising thermal performance.
• These materials offer a promising solution for thermal management challenges in advanced electronic devices.