A Low-Frequency Micro Accelerometer Based on Three-Lobed Leaf Spring and a Focus Probe

Abstract

A new micro accelerometer is proposed to measure and reduce low-frequency vibrations actively. It is mainly composed of a seismic mass, a leaf spring, and a focus probe modified from a digital versatile disc (DVD) pickup head. When a vibration occurs, the leaf spring will exhibit an elastic deformation; the seismic mass will move up and down due to the effect of inertia, whose displacement can be detected by the focus probe. Therefore, the measured acceleration can be obtained. The accelerometer was designed, and its proper parameters were obtained. The accelerometer was calibrated and tested using a high-precision vibration generator. The experimental results demonstrate that the proposed accelerometer has a sensitivity of 10.8 V/g, a resolution of 3.0 × 10 -4 g, and a working frequency range of 1-10 Hz. Also, the uncertainty of the accelerometer was analyzed in detail and an evaluation result of 7.0 × 10 -4 g (K = 2) was obtained. It can be used to detect the low-frequency microvibrations in high-precision measurement and machining fields.

Optical Accelerometers for Detecting Low-Frequency Micro-Vibrations

“…The resonant frequency in the x and y directions of a cantilevered beam is not significantly greater than the resonant frequency in the z-direction, and vibrations in the x and y directions exert a greater effect on the output of the accelerometer. Therefore, Li et al designed an accelerometer with a fully symmetric leaf spring (as shown in Figure 4); it has a resolution of 0.3 mg and measurement uncertainty as low as 0.07 mg (K = 2) [22]. To improve the sensitivity of optical accelerometers, Cheng et al modeled an optical accelerometer by using sensitivity analysis and improved its sensing optical path to achieve a resolution as low as 4 µg [23].…”

“…An optical accelerometer based on the LTG method and a fully symmetrical leaf spring-type elastic mechanism can achieve a low-frequency response down to 0.4 Hz and a high resolution of 0.3 mg. design of Chu et al by using the moving part of the voice coil motor inside a DVD pickup head as the elastic mechanism; they reduced the size of the accelerometer while improving its sensitivity to 24.4 V/g [21]. The resonant frequency in the x and y directions of a cantile vered beam is not significantly greater than the resonant frequency in the z-direction, and vibrations in the x and y directions exert a greater effect on the output of the accelerometer Therefore, Li et al designed an accelerometer with a fully symmetric leaf spring (as shown in Figure 4); it has a resolution of 0.3 mg and measurement uncertainty as low as 0.07 mg (K = 2) [22]. To improve the sensitivity of optical accelerometers, Cheng et al modeled an opti cal accelerometer by using sensitivity analysis and improved its sensing optical path to achieve a resolution as low as 4 µg [23].…”

“…In summary, optical accelerometers based on optical path modulation are characterized by a simple structure and convenient signal processing; high sensitivity can be achieved by optimizing the mechanical [22] or optical sensing units [23]. However, the measurement accuracy of this type of optical accelerometer is directly related to the structure of the optical path and the performance of the photodetector.…”

Parallel Microdispensing Method of High-Viscous Liquid Based on Electrostatic Force

“…Microdispensing of high-viscous liquid is a fundamental task in various industrial productions [1][2][3]. Taking the fabrication of microdevices as an example, many droplets of high-viscous adhesive are required for the connection and encapsulation process [4,5]. To improve efficiency, the development of parallel microdispensing is imperative, which can permit many droplets to be efficiently transferred onto the target.…”