Directional transport of molecular mass on graphene by straining

• We reveal a fundamental law of directional transport of molecular mass by straining.
• Directional transport of molecular mass is programmable by devising straining scheme.
• Generally applicable to a wide range of molecular mass and platform materials.

Directional transport of molecular mass is essential in enabling desirable functions in nano-devices, but is often challenging to achieve. In this letter, we combine theoretical analysis and molecular simulations to demonstrate a facile mechanism of directional transport of molecular mass on graphene by a simple stretch. We reveal that stretch-induced strain gradient in graphene leads to a net transport force that is sufficient to drive molecular cargo on the graphene in a directional fashion. The large elastic deformability of graphene and the van Der Waals nature of the transport force allow for programmable directional transport of various types of molecular cargo (e.g., graphene flake, carbon nanotube, fullerene, and gold nanoparticle) under the same mechanism. The present findings suggest a fundamental law of directional transport of molecular mass by straining.