Towards graphene based flexible force sensor

Monolayer graphene transferred over flexible polyvinyl chloride (PVC) substrate combined with closely packed layer of nano-spheres (NSs) is fabricated for force sensing application. The force was applied from vertical direction through NSs which acts as lateral strain enhancers. The stack persuades lateral in-plane strain in the monolayer graphene for the applied vertical pressure through NSs. The electrical measurements demonstrate that the graphene layer is able to respond for soft touch range commonly perceived by human beings. The sensing stack was fabricated using simple approaches such as hot lamination graphene transfer process and drop casting of NSs. The device structure is flexible to conformably cover the nonplanar surface for applications such as large area pressure sensing and robotic e-skin.