Quantifying the local mechanical properties of twisted double bilayer graphene

Nanomechanical measurements of minimally twisted van der Waals materials remained elusive despite their fundamental importance for device realisation. Here, we use Ultrasonic Force Microscopy (UFM) to locally quantify the variation of out-of-plane Young's modulus in minimally twisted double bilayer graphene (TDBG). We reveal a softening of the Young's modulus by 7% and 17% along single and double domain walls, respectively. Our experimental results are confirmed by force-field relaxation models. This study highlights the strong tunability of nanomechanical properties in engineered twisted materials, and paves the way for future applications of designer 2D nanomechanical systems.

Automated summary

Using Ultrasonic Force Microscopy (UFM), researchers have quantified the variation of out-of-plane Young's modulus in minimally twisted double bilayer graphene (TDBG). They found a softening of the Young's modulus by 7% and 17% along single and double domain walls, respectively. This study highlights the tunability of nanomechanical properties in engineered twisted materials and opens new possibilities for future applications of designer 2D nanomechanical systems.