Controllably Straining Graphene Ribbons via Electrostatic In-Plane Actuation

Bending monolayer ribbons of two-dimensional materials in-plane has previously demonstrated moiré patterns with highly tunable wavelengths and low disorder. Previously, in-plane bending was achieved by pushing monolayer ribbons with an atomic force microscope (AFM) tip, with samples showing uniform twist angle variations and strain gradients. The AFM bending method, however, does not allow for dynamic control of ribbon deflection, which follows a simple cantilever bending model. Actuation of graphene ribbons on an hBN substrate via an in-plane electrostatic force provides a comparable bending mechanism to mechanical manipulation but has the added benefit of in-situ control over the graphene deflection. Electrostatic actuation of the graphene further expands the range of twist angles and strain values that can be achieved with a single device. Additionally, this demonstration of graphene actuation on hBN is promising for the creation of highly programmable devices and paves the way for the development of novel, 2D materials-based MEMS.