On Driving Micro Motors for MEMS with a Micro Driver Based on Three-Phase Sinusoidal Signals

Micro electromechanical system (MEMS) technologies, which have been widely used in robotics and automation, are being ported into medical embedded systems. A key change MEMS brings is the mechanic locomotion to physically move the embedded systems, which is usually actuated by a micro motor. However, classic motor driver and control cannot be used to drive the micro motor due to its tiny size and unique motor mechanisms. This paper presented a micro three-phase sinusoidal signal driver for micro brushless motor. The driver enables precise adjustment to the speed and output torque of the micro motor without any feedback. To explain the physical principles of the driver, we first analyze the compound Magnetic Motive Force (MMF) of three-phase sine-wave voltage. Then we describe the traditional way to drive the micro motor. After explaining the theoretical logic, we present the design details of the driver. After verifying the design with simulation, we implement the driver with physical circuits whose measured results are also shown. We believe that the correct design and implementation of the driver will enable active movements of embedded systems in medical environment.