Abstract: A diaphragm air pump comprises a pump chamber, a diaphragm and one or more piezoelectric beams or bimorphs. Fluid flows into the pump chamber and then flows out of it, the diaphragm is provided within the pump chamber, and one or more central openings are formed in the diaphragm. One or more central check valves are provided in the central openings. The diaphragm is just bonded with piezoelectric beams, not fixed to the lower housing of the pump chamber in order to get large displacement. With the provided diaphragm air pump, it is possible to actively adjust the air quantity according to the requirement for fuel cell or a part-to-be-cooled, and it is also possible to reduce noise and power consumption compared with a conventional fan type cooler or air pumps.

Abstract: A diaphragm air pump comprises a pump chamber, a diaphragm and one or more piezoelectric beams or bimorphs. Fluid flows into the pump chamber and then flows out of it, the diaphragm is provided within the pump chamber, and one or more central openings are formed in the diaphragm. One or more central check valves are provided in the central openings. The diaphragm is just bonded with piezoelectric beams, not fixed to the lower housing of the pump chamber in order to get large displacement. With the provided diaphragm air pump, it is possible to actively adjust the air quantity according to the requirement for fuel cell or a part-to-be-cooled, and it is also possible to reduce noise and power consumption compared with a conventional fan type cooler or air pumps.

Abstract: A system and method for determining attitude using triaxial micro electro-mechanical accelerometer-magnetometer sensors. The triaxial accelerometer-magnetometer sensors measure the triaxial components of the local gravity and magnetic field along three sensing axes of the sensors. The misalignment of the components due to nonorthogonal triaxial assembling of the sensors is estimated via performing three optical alignments and is further compensated in the sensing outputs. A micro-cube with three orthogonal coated mirrors is fixed on the circuit board of the system for implementing the optical alignments. The compensated sensing components are processed to figure out the attitude using Orientation Cosine Conversion of the local gravity and magnetic field. The computation for determining the attitude is based on the inverse tangent of the ratio of the processed components, which is more precise than the computation using the absolute values of the components.

Abstract: This present invention is subjected to the field of instrument & measurement technology based on Micro Electro-mechanical Systems (MEMS). A micro azimuth-level detector comprises multi-sensors (triaxial silicon accelerometers with the processing circuit and triaxial silicon magnetometers with the processing circuit), A/D converter for converting the analog signals of the sensors to the digital signals, microprocessor in which the signal-processing and attitude computation are carried out, RS-232 for connecting the microprocessor with PC, and Operation-Display interface. An attitude computation method uses the Orientation Cosine Conversion of the earth's gravity and magnetic field.