For the development of high precision mobile microrobots with a size of about one cm3, capable of micromanipulation tasks, small and precise actuators have to be developed in order to provide the microrobot and its manipulation tools with the required degrees of freedom. The main requirements for these actuators are to be small and precise. In this paper we propose two variants of a high precision miniature rotary microactuator which are developed to fit into a cm3-sized mobile microrobot. These rotary microactuators are driven by piezoelectric actuators and are based on the inertial drive principle. The first version has the advantage to have a thickness of 0.5 millimetres and an outside diameter of 8mm (without the output arm) while the other one is easier to fabricate and to mount on the robot while being a bit wider (1.4 mm). The design, the working principle and some measurement results of those actuators are presented. A version with an integrated gripper is also presented and the integration on a mobile microrobot is discussed.