Theoretical strength and rubber-like behaviour in micro-sized pyrolytic carbon

Area of Science:

• Materials Science
• Nanotechnology
• Mechanical Engineering

Background:

• Achieving materials with high strength, deformability, ductility, large elastic limit, and low density simultaneously is a significant challenge.
• These properties are typically mutually exclusive in conventional materials.

Purpose of the Study:

• To create micro-sized pyrolytic carbon with a unique combination of mechanical properties.
• To overcome the limitations of existing structural materials.

Main Methods:

• Utilized a combination of two-photon lithography and high-temperature pyrolysis.
• Fabricated micro-sized pyrolytic carbon structures.

Main Results:

• Achieved tensile strength of 1.60 ± 0.55 GPa and compressive strength near the theoretical limit (~13.7 GPa).
• Demonstrated a substantial elastic limit of 20-30% and low density (~1.4 g cm⁻³).
• Exhibited specific compressive strength of 9.79 GPa cm³ g⁻¹, surpassing most structural materials.

Conclusions:

• The developed pyrolytic carbon possesses an unprecedented combination of mechanical properties.
• Microstructures with curled graphene fragments and covalent bonds enable exceptional performance.
• Pillars exhibit size-dependent mechanical behavior, with smaller ones showing rubber-like elasticity.