The following are the advantages and disadvantages of silicon resonant pressure sensors compared with other common types of pressure sensors:
Advantages
High precision: Silicon resonant pressure sensors are based on the vibration principle of resonators. They calculate the pressure value by measuring the impact of pressure on the vibration frequency of the resonators. This measurement method enables them to achieve extremely high resolution and measurement precision. Generally, the precision can reach 0.01% or even higher, which is 1 to 2 orders of magnitude higher than that of traditional pressure sensors such as strain gauge type and piezoresistive type. It can meet various high-precision measurement requirements, for example, the precise measurement of parameters such as static pressure and airspeed in the aircraft air data system in the aerospace field.
High stability: Silicon material itself has high elasticity and high stability. Moreover, the internal structure of the sensor is simple, without mechanical moving parts, and is not easily affected by factors such as wear and fatigue. Therefore, it has long-term stability and reliability. It doesn't need to be calibrated for five consecutive years of operation, and the influences of temperature and static pressure can be neglected. It is suitable for application scenarios with extremely high requirements for stability, such as the control of chemical production processes in industrial automation.
Strong anti-interference ability: The output is a frequency signal. This digital signal is not easily affected by external factors such as electromagnetic interference. Compared with some pressure sensors that output analog signals, it can transmit measurement data more accurately in complex electromagnetic environments and can be applied to environments with relatively strong electromagnetic interference, such as the engine compartment of automobiles.
Low power consumption: Due to its simple internal structure and the absence of complex mechanical movements or high-energy-consuming components, its power consumption is extremely low. This is very advantageous for some portable devices powered by batteries or systems with strict requirements on energy consumption, such as being applicable to portable medical monitoring devices.
Small size, light weight and easy integration: Silicon resonant pressure sensors adopt micro-nano manufacturing processes, which can realize the pressure measurement function within a relatively small size. Moreover, they are easy to be integrated with other electronic components or systems, and can meet the needs of various miniaturized and lightweight devices.
Disadvantages
Higher cost: The manufacturing process of silicon resonant pressure sensors is relatively complicated. It requires high-precision micro-nano processing technologies and special materials, resulting in relatively high manufacturing costs and more expensive product prices. To some extent, this restricts its promotion in some large-scale application scenarios that are sensitive to cost, such as ordinary household consumer electronic products.
Limited measurement range: Compared with some pressure sensors with a wide measurement range, the measurement range of silicon resonant pressure sensors is relatively narrow. Generally, it is suitable for the measurement of medium and low pressure ranges. For some special application scenarios that require the measurement of extremely high or extremely low pressures, it may not be able to meet the requirements. For example, there are limitations in applications such as deep-sea high-pressure detection or ultra-high vacuum environment measurement.
Sensitive to temperature changes: Although silicon resonant pressure sensors themselves have relatively good temperature stability, they may still be affected to some extent under some extreme temperature conditions. Moreover, their temperature compensation technology is relatively complicated, requiring more precise temperature compensation circuits or algorithms to ensure the measurement accuracy within a wide temperature range, which increases the complexity and cost of the system.
Complex excitation and detection methods: Silicon does not have piezoelectricity, so it is relatively difficult to achieve the excitation and reception of resonance. Special excitation methods such as electrostatic excitation, electromagnetic excitation, and thermoelectric excitation, as well as corresponding detection techniques, need to be adopted. The implementation of these excitation and detection methods is rather complicated, which increases the design and manufacturing difficulties of the sensor and also puts forward higher requirements for its reliability and stability.