Microsystem design involves the mixing of two main disciplines: mechanical engineering and electronics. Multidisciplinary design approach is not easy to implement and becomes more difficult when the challenge consists in simultaneously handling new knowledge that characterizes the field of microsystem industry. We present herewith a new multidisciplinary engineering approach used to lead the detailed design of micro-accelerometers based on virtual tools. Virtual prototyping that is usually implemented in one sole domain of competence is developed to be manipulated by either experts from electronics or mechanics. This new tool improves collaboration and the rapid identification of highly satisfying solutions. The virtual tool allows exploration of micromechanical devices and system design issues and objectives. It uses interactions with the designer in order to achieve solutions integrating the physics rules of the design and the experience of the designer.