Structural Design of a Compact in-Plane Nano-Grating Accelerometer
YAO Bao-Yin**, ZHOU Zhen, FENG Li-Shuang, WANG Wen-Pu, WANG Xiao
Key Laboratory of Micro-nano Measurement-manipulation and Physics (Ministry of Education), Beihang University, Beijing 100191 Fundamental of Science on Novel Inertial Instrument & Navigation System Technology Laboratory, Beihang University, Beijing 100191
Abstract：A combination of large mass, weak spring and nano-grating is the key for a nano-grating accelerometer to measure nano-G acceleration. A novel compact nano-grating accelerometer integrating a large mass with nano-grating is proposed. First, the numbers of diffraction orders are calculated. Then, structure parameters are optimized by finite element analysis to achieve a high sensitivity in an ideal vibration mode. Finally, we design the fabrication method to form such a compact nano-grating accelerometer and successfully fabricate the uniform and well-designed nano-gratings with a period of 847 nm, crater of 451 nm by an FIB/SEM dual beam system. Based on the ANSYS simulation, a nano-grating accelerometer is predicted to work in the first modal and enables the accelerometer to have displacement sensitivity at 197 nm/G with a measurement range of ±1 G, corresponding to zeroth diffraction beam optical sensitivity 1%/mG. The nano-gratings fabricated are very close to those designed ones within experimental error to lay the foundation for the sequent fabrication. These results provide a theoretical basis for the design and fabrication of nano-grating accelerometers.
2012, Vol. 29 
