A calculation and test method for the natural frequency of a high-g micro accelerometer with complex structures is presented. A universal formula for natural frequency, which can significantly simplify the structural design process, is deduced and confirmed by experiment. A simplified analytical model is established to describe the accelerometer＇s mechanical behavior and deduce the formula for the natural frequency. Finite element modeling is also conducted to evaluate the natural frequency of the micro-accelerometer and verify the formula. The results obtained from the analytical model and the finite element simulation show good agreement. Finally, a shock comparison method designed for acquiring the high frequency characteristics of the accelerometer is introduced to verify the formula by testing its actual natural frequency.
Resonant tunnelling diodes （RTDs） have negative differential resistance effect, and the current-voltage characteristics change as a function of external stress, which is regarded as mesc-piezoresistance effect of RTDs. In this paper, a novel micro-accelerometer based on AlAs/GaAs/In0.1Ga0.9As/GaAs/AlAs RTDs is designed and fabricated to be a four-beam-mass structure, and an RTD-Wheatstone bridge measurement system is established to test the basic properties of this novel accelerometer. According to the experimental results, the sensitivity of the RTD based micro-accelerometer is adjustable within a range of 3 orders when the bias voltage of the sensor changes. The largest sensitivity of this RTD based miero-accelerometer is 560.2025 mV/g which is about 10 times larger than that of silicon based micro piezoresistive accelerometer, while the smallest one is 1.49135 mV/g.
This paper reports the piezoresistive effect of a resonant tunneling diode （RTD） in a microstructure. The fourbeam structure is analyzed and fabricated by positing RTDs at the stress sensitive regions. Stress along the [110] orienta- tion and [110]ientation induces a change in the RTD＇s current-voltage （I-V） curves,i, e., the meso-piezoresistance variety,mainly in its negative different resistance （NDR） region. By different methods,the mechanic-electric coupling characteristic of RTD is studied and the consistent 10^9Pa^1 piezoresistive coefficients are discovered.
