The design stage of the development of a MEMS device is crucial if its fabrication is to be right the first time. Computer-aided design (CAD) helps to accelerate this process and provides a cost-effective method in the prediction and optimization of device characteristics. This paper describes this design process, focusing on the conceptual design phase in the development of microactuators as part of the actuator component of a Virtual Reality-prototyping CAD tool. To create the functions and database required for this tool, the effects of parameters such as temperature, pressure, strain, acceleration etc., on the microactuator have to be evaluated. To achieve this, a comprehensive analysis of the most relevant parameters affecting the different types of microactuators based on their force-producing principle is required. This is a huge and lengthy task. It includes the estimation of mechanical performance of the device with variation in its geometrical structure and the optimization of the variations with respect to their static and dynamic performance, for example linearity and resonant frequency. It aids in the analysis of constraints in the geometrical design for robustness in its manufacture. In this paper we analyze the requirements, the functions and database entries, via an application case example for a membrane micropump. Its structure is studied in order to demonstrate the feasibility of using this device as a pump that is able to move air from one chamber to another. In this example we look at the underlying models that warrant a desired performance and whose calculations results in the geometries and operational parameters, such as the flow of air or liquid, the deflection of the membrane, etc. These results serve as input to the Virtual Reality Visualizations module and displayed with time and size scaled animations.