Basic elements › Materials › Composite materials › Carbon composites

LES NANOTUBES DE CARBONE (CNT)

MENU

2. General description

Carbon nanotubes (CNT) are cylindrical structures made of graphene sheets rolled at the nanometric scale. Derived from nanotechnologies, they exhibit exceptional mechanical, thermal, and physical properties, far superior to those of traditional Materials.

Presenting environmental hazards and health risks, carbon nanotubes have been subject to REACH regulation since 2020.

In watchmaking, their use remains very marginal and essentially experimental, particularly in the development of hairsprings composites aimed at improving the performance of the Regulating organ.

3. Structure and behavior

Carbon nanotubes can be:

• Single-walled (SWCNT) → a single layer of graphene
• Multi-walled (MWCNT) → several concentric layers

They are generally used:

• in the form of networks
• integrated into a composite Die

At the macroscopic scale, their properties strongly depend on:

• their orientation
• their dispersion
• their density

4. Watchmaking Applications

In watchmaking, carbon nanotubes have been explored experimentally for:

• Hairsprings composites

Their main interest lies in their ability to:

• offer very stable Elasticity
• reduce sensitivity to thermal variations
• eliminate the effects of magnetism

5. Advantages and Limitations

Advantages

• Exceptional mechanical properties
• Very great lightness
• Remarkable thermal stability
• Non-magnetic
• High fatigue resistance

Limitations

• Complex implementation
• Difficulty of large-scale production
• Properties dependent on structuring
• Very high cost
• Still experimental use
• Difficulty of industrial reproducibility
• Subject to REACH regulation (hazards to health and the environment)