Abstract
A multistage sensing device includes a substrate, a deformable unit, and a sensor unit. The deformable unit has a first body disposed on the substrate, and a second body disposed on the first body and opposite to the substrate. The sensor unit includes a first sensor element and a second sensor element that are disposed in the deformable unit. The first sensor element is disposed between the second sensor element and the substrate. The second sensor element is operable to measure deformation of the second body when an external force is applied to the deformable unit. The first sensor element is operable to measure deformation of the first body when the first body is deformed by the deformation of the second body.