MEMS microgravity sensor chip with quasi-zero stiffness characteristic preloaded based on electric heating

Abstract

A MEMS microgravity sensor chip with the quasi-zero stiffness characteristic preloaded based on electric heating comprises a monocrystalline silicon substrate, a silicon dioxide insulating layer growson the monocrystalline silicon substrate, a monocrystalline silicon structure layer is bonded on the silicon dioxide insulating layer, and a MEMS acceleration sensor chip is manufactured in the monocrystalline silicon structure layer; the MEMS acceleration sensor chip comprises a chip frame, four corners of the chip frame are respectively provided with a group of electrode anchor points, an electric heating driving unit composed of V-shaped beams is connected between each group of electrode anchor points, the V-shaped beams are connected with a middle arm, the middle arm is connected with a mass block through a limiting self-locking mechanism and a spring, and the limiting self-locking mechanism is matched with the chip frame; except the electrode anchor points and the chip frame, the monocrystalline silicon substrate and the silicon dioxide insulating layer below the rest part are corroded; an electro-thermal effect is adopted to carry out axial displacement loading on the spring, the mass block obtains a section of working interval with quasi-zero rigidity in the vertical direction on the premise that the vertical rigidity of the spring is not reduced, and the mass block can beused for microgravity acceleration detection and has the advantages of being simple in structure and the like.

Description

technical field [0001] The invention relates to the technical field of acceleration sensors, in particular to a MEMS microgravity sensor chip with quasi-zero stiffness characteristics based on electrothermal preloading. Background technique [0002] The earth's gravity field contains a wealth of physical information. As human production activities gradually go underground, the measurement environment and indicators of gravity acceleration become more stringent. People's demand for high-resolution and high-precision microgravity acceleration detection technology is increasing. eager. With the iterative development of manufacturing technology, micro-electromechanical system (MEMS) acceleration sensors with small size, low energy consumption and high precision are increasingly replacing traditional acceleration sensors and becoming the mainstream. Whether using optical, capacitive or resonant measurement methods, the spring-mass system with high sensitivity is the core structu...

AI Technical Summary

Problems solved by technology

[0004] Middlemiss and others at the University of Glasgow applied the MEMS manufacturing process to the acceleration sensor, and used the anti-spring structure to design the spring-mass system of the acceleration sensor, and obtained a system with ultra-low in-plane vibration resonance frequency; however, the characteristic size of the anti-spring structure is very small , has high requirements on the manufacturing process, and has the disadvantage of narrow bandwidth

[0005] To sum up, since the sensitivity of the spring-mass system in the vertical direction is inversely proportional to its stiffness in this direction, if the vertical stiffness of the spring is simply reduced in order to increase its sensitivity, the bearing capacity of the system will also decrease , that is, the mass of the connected mass decreases and the acceleration it can withstand is also very small, so the sensitivity direction stiffness of the main structure of the existing in-plane motion MEMS acceleration sensor cannot be made very low, and the sensitivity of the mass block is therefore limited, and the low g The resolution of value detection still needs to be improved

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