Research progress of low-power carbon monoxide sensors

Low-power carbon monoxide sensor is an important guarantee for safe coal mining and a key foundation for distributed wireless sensing technology. In this paper, the working principle of low-power carbon monoxide sensor is described, and the latest research progress of electrochemical and semiconductor carbon monoxide sensor is introduced. This paper analyzes their advantages and disadvantages and proposes the development direction and prospects of low-power carbon monoxide sensor. ① The electrochemical carbon monoxide sensor is mainly composed of electrodes and electrolyte. There are two-electrode structure and three-electrode structure. The two-electrode electrochemical carbon monoxide sensor has no reference electrode. It has a simple structure and is easy to be designed and manufactured. The sensor has a low cost and is suitable for the monitoring of low-concentration carbon monoxide. The three-electrode electrochemical carbon monoxide sensor introduces a reference electrode with a larger range and higher accuracy, but the cost is high. The electrochemical carbon monoxide sensor has a short response time and has the prospect of distributed wireless sensing applications. The research focus is on the preparation of platinum-carbon composite electrodes. However, the electrochemical carbon monoxide sensor still uses liquid solvent, which has the risk of liquid leakage. Moreover, it is difficult to realize micro-miniaturization. The future development trend is to avoid the use of liquid solvents, to study all solid-state electrochemical carbon monoxide sensors, and to control the porosity to shorten the response and recovery time. On the other hand, the trend is to find cheap and efficient electrode materials to reduce sensor costs. In addition, manufacturing micro-miniaturized electrochemical carbon monoxide sensor is also an important part of future work. ② The semiconductor carbon monoxide sensor can be divided into non-micro-heating plate type and micro-heating plate type. The non-micro-heating plate type carbon monoxide sensor uses a ceramic tube substrate or an alumina plate substrate. Due to the large heater size, severe heat conduction and high power consumption with usually above 100 mW, it is difficult to be used in distributed wireless sensing occasions. The micro-heating plate type carbon monoxide sensor has low thermal quality, which can greatly reduce the operating power consumption of the heater. It is also compatible with integrated circuit process. A system-on-chip carbon monoxide sensor can be obtained, which reduces the power consumption of peripheral circuits and is suitable for IoT applications. The micro-heating plate type carbon monoxide sensor is smaller than solid electrolyte electrochemical carbon monoxide sensor, and has the advantages of low cost, high sensitivity and easy on-chip integration. However, it is easily affected by humidity and the baseline is easy to drift. The future research direction is to improve the modification of sensitive materials, optimize the packaging process, and use intelligent algorithms to self-calibrate the baseline. It is proposed to use zeolite to modify sensitive materials to reduce the impact of humidity on the sensor, or use a water-repellent membrane such as polytetrafluoroethylene in the packaging process. The intelligent algorithm can use a combination of support vector machines and artificial neural networks or artificial intelligence algorithms. In the future, it is hoped that high-efficiency edge computing can be achieved to improve the efficiency and accuracy.