This work reports a class of silicon micromachined millimeter scale electrostatic actuator capable of both axial and lateral in-plane displacement with a relatively high energy density. The actuator is comprised of a large-scale integrated array of individual parallel-plate electrostatic cells. The force and displacement of cells within the array add up providing relatively large actuation force and displacement output for the actuators. The non-conventional fabrication process allows realization of submicron transduction airgaps within the actuator cells lowering the actuation voltage. The fabrication process also allows electrical isolation of different cells within the array so that different sections of the actuator ribbon can be actuated independently enabling lateral deformation of the actuator ribbon in addition to axial contraction. Axial in-plane displacement of up to 20.50 µm has been shown for a 2010 µm × 1000 µm fabricated actuator. The actuator output force is as high as 10.3 mN demonstrating maximum energy density of 1.11 mJ/cm3. The same actuator ribbon demonstrated lateral displacement of 10.11 um.