A micro-electromechanical system (MEMS) device can include a substrate and a first beam suspended relative to a substrate surface. The first beam can include a first portion and a second portion that are separated by an isolation joint made of an insulative material. The first and second portions can each include a first semiconductor and a first dielectric layer. The MEMS device can also include a second beam suspended relative to the substrate surface. The second beam can include a second semiconductor and a second dielectric layer to promote curvature of the second beam. The MEMS device can also include a third beam suspended relative to the substrate surface. The third beam consists essentially of a first material. The second beam is configured to move relative to the third beam in response to an acceleration along an axis perpendicular to the surface of the substrate.