Since the cantilever-type silicon accelerometer was introduced by L.M. Roylance and J.B. Angell in 1979, micromachined accelerometers have been used in various industry fields. There are several methods for sensing the acceleration of such micromachined accelerometers, including capacitive, piezoresistive, piezoelectric, resonant, and optical methods. Among these, the most commercially used methods are capacitive, piezoresistive, and piezoelectric detection. Among them, the piezoresistive detection method measures high-shock over thousands of g without additional circuit or packaging in the most stable way. The measurement of high-shock over thousands of g is highly significant in various fields such as vehicle collision test, building blast test, oil drilling, and manufacturing bomb fuses. Thus, research on the manufacture and application of high-shock piezoresistive accelerometer have been actively conducted.
In this paper, a high-shock (2,000 g) accelerometer with a plate spring is presented. The acceleration sensor comprised of the presented plate spring has merits of relatively simple manufacturing process and possibility of precisely controlling the dimension of the spring. In addition, the sensor has high structural stability because it is manufactured in a form where the plate spring surrounds the mass body of the sensor. Detailed design of the dimensions of the presented acceleration sensor was determined through an optimum design process using commercial software. Furthermore, the presented acceleration sensor was manufactured through a micro-machining process based on semiconductor process technology. The performance of the presented acceleration sensor was evaluated by measuring the sensitivity, cross-sensitivity, and over-shock survivability of the sensor.
When a shock of 2,000 g was applied, the sensitivity of the manufactured acceleration sensor was 34.6 μV/g. When a shock within 2,000 g was applied, the crosssensitivity of the acceleration sensor was measured to be 2.5% or below. The presented acceleration sensor exhibited a stability to the extent that it was not destroyed even under a shock of over 6,000 g, which was three times the sensing range, and the crosssensitivity was 15% or below the measured sensitivity. The presented acceleration sensor is expected to be applied in various fields where measurements of high-shock over thousands of g are required.