Abstract: An omni-directional wall-climbing wheeled microrobot is presented.The integral design with driver and adhesive is realized by integrating the axial flux electromagnetic micromotor and the permanent-magnetic wheel.An omni-directional wall-climbing mechanism is designed by using a set of steering gears and three standard permanent-magnetic wheels.The required torque and magnetic force for the movement of the microrobot are derived by dynamic analysis. The sizes of permanent-magnetic wheels are optimized in combination with their own design constraints by ANSOFT and Pro/Engineer simulation,so as to reduce the unnecessary torque consumption under the condition that the load of the microrobot remains the same.The simulation and experimental results demonstrate the feasibility of these concepts.