SiC是一种新型气敏材料，它对气体具有优良的吸附特性，在气敏元件的研发领域具有非常高的研究价值。本文基于密度泛函理论模拟计算了CO气体在SiC表面和Ni掺杂SiC表面的吸附性能和特征。分别从吸附系统空间结构变化、吸附能、态密度、密立根电荷布居及电荷密度差等几个方面，对比分析了CO在其表面不同吸附位置的吸附特征。结果表明对于CO在SiC(001)表面吸附，桥位是一个敏感的吸附位置；而对于CO在Ni掺杂SiC(001)表面吸附，fcc位是比较敏感的位置。并发现Ni掺杂明显提高了SiC(001)表面的活性，提高了气体吸附的概率。相关的结论将用于指导CO气体在SiC材料表面吸附实验的实施，同时对SiC瓦斯传感器的研发具有科学的理论指导价值。 在传感器电路设计中，引入了蔡氏混沌电路以提高气敏传感器的灵敏度。利用蔡氏电路对电路的初始条件极端敏感的特性，来检测低浓度的瓦斯气体。通过改变电路中敏感电阻的阻值获得电路产生不同的混沌相轨图，进而关联瓦斯气体的浓度和成分。出于对电路灵敏度的更高要求，在蔡氏电路的基础上，对其进行了新的改进，使得电路的灵敏度有了质的改善，而且电路的性能也得到了提升。此外，对比了模拟和数字两种方式实现了蔡氏混沌电路的优缺点，提出了采用数字方式实现电路设计的可行性。 在低浓度瓦斯传感器设计电路的基础上，基于嵌入式平台设计了它的外围电路，包括声光报警电路、LCD显示电路、实时监控电路等。使得瓦斯传感器具有智能化的设计和比较完善的功能。同时大大提高了电路的集成度，方便后期产品的升级和集成。为客户带来极大地便利，可以广泛的应用到生产和生活中，尤其是运用的矿井煤矿开采方面，使得煤矿的开采环境变得更加安全。

SiC, a new type of gas sensitive material, is widely used in various industrial production fields, because of its superior performance. The adsorption performance of CO adsorbed on the SiC(001) surface and the one of Ni-doped SiC(001) surface are investigated by using the DFT-GGA calculation method in this paper. The adsorption characteristic of CO adsorbed on SiC(100) surface and Ni-doped SiC(001) surface are contrastively analyzed based on the changes of bond structures, adsorption energy, density of states, Mulliken population and charge density difference. The results show that bridge site is a favorable adsorption site for CO on SiC(001) surface, and fcc site is sensitive site to CO on Ni-doped SiC(001) surface. The Ni doped can increase the activity of SiC(001) surface, raising the possibility of gas adsorbed on SiC(001) surface. The results are useful to guide the implementation of the adsorption experiment of CO on SiC(001) surface and also have important significance to study on the SiC gas sensor. In order to improve the sensitivity of gas sensor circuit, the Chua’s chaotic circuit is introduced in circuit design. The Chua’s chaotic circuit is used to detect of low concentration of gas because it is sensitive to the initial value of circuit. We will obtain different chaotic phase track diagram by changing the initial value of circuit to calibrate the concentration of gas. The circuit on the basis of Chua’s circuit is upgraded to match the requirements for circuit sensitivity. That makes the sensitivity of the circuit with a qualitative improvement and the performance of the circuit improved. Ulteriorly, we use the analog and digital ways to realize the Chua’s circuit and analyze the advantage and disadvantage of them respectively. The feasibility of digital circuit design is proposed. A series of peripheral circuit are designed using the embedded platform based on the sensing circuit, which include the sound and light alarm circuit, display circuit, real-time monitoring circuit. The gas sensor will have relatively fully function, intelligent design, convenient upgrade and integrate products in the future. The products can be widely applied to the industry and daily life, especially the use of coal mine, made the mine mining become more safety.