the emergence of micro-electro-mechanical system (MEMS) technology for the development and application of chemical sensor technology is very important, especially in those included in harsh environments or are unsafe operation. As to be in the following paper, chemical micro sensor can provide specific way of information, it is able to decrease the cost of a system or process at the same time, greatly improve the safety and reliability. Such information way also can be applied to improve the system performance and reduce environmental impact. Chemical sensors data can also be for physical measurement, such as temperature, pressure, heat flux, measurement, more can comprehensively improve the system, and then expand its performance.

However, even the traditional chemical sensor technology application of micron size of certain problems exist. Chemical sensors usually requires special design or custom, can in a knot under the environment of operation. One example is. The most common to meet the requirements of a certain application chemical sensors under the request of another application does not provide enough functionality. Environmental requirements, needs, the more fully, "the more we need to modify the existing chemical sensor technology in order to meet these requirements, or. According to the current demand to develop new chemical sensor technology. Judge & mdhistriadn; A chemical sensor can satisfy the application, will be references to the corresponding four basic parameters: the sensitivity, selectivity, response time and stability. Refers to the sensor sensitivity for the detection of chemical species within the scope of build by laying bricks or stones and required skills.

Selectivity refers to the sensor in the presence of interfering with gas environment of sensitive types of detection ability, it also can generate a sensing response. Reaction time is when the chemical environment change, sensor intention give a signal (usually 90%) is defined as the steady-state signal takes time. Finally, the stability is refers to the sensor over time in a given environment change in the baseline and reaction degree, in a nutshell, the macro and micro chemical sensing system chemical sensing system, all need & mdhistriadn; Can accurately measure in a given environment sensitive types of sensor, request it in the application has enough strong and fast response characteristics, and these reactions within the scope of its design working life are not allowed to have bigger drift, from the perspective of applications. To find a can provide the demand of sensitivity, selectivity, response time and the stability of the appropriate sensor material is often very difficult.

Micro processing involved in the aspects of chemical sensors, is more than just a common measure of the sensor to reduce the so simple. The whole process needs to produce a particle can be used as a visual sensing material, so that you can in the miniaturized system part materials are required for preparation. Particles, for example, a visual body chemical sensor can be made by powder as raw materials for the original. Placed in a single version of the wire, and then sintered at high temperature, in order to form the sensor. However, using the same original material, the material to those substrate to form a smaller or more micro sensor, usually don't have the feasibility. Specifically, sensor material of thin film or thick film must be from deposition to the substrate, as a minimum, must also be compatible with sensors and can realize the connection with the outside world. The following with sensors membrane substrate, in a typical sintering small particles of sensing materials will not be left behind.
In addition, for many chemical sensor has a surface sensor performance, the effects of miniaturization can be very large, but also to significant changes in sensor sensitivity and the reaction time. These effects as part of the reason is that within the sensor film usually sputtering process system, such as process more influence on the material properties. Thin film materials & other; Surface & mdhistriadn; Throughout the volume & Watson sensor ; Ratio is greater than the result of the material body, therefore, surface effect for body sensor effect is small, it will bring great influence in film sensors. These situations will greatly affect the hurt and confused.

For example, when exposed to high temperature environment, oxide will appear on the surface of the sensor. In the material, the oxide accounts for only a small part of sensor size, and in thin film materials, the same thickness of the oxide has occupied much of sensor volume. If the sensor detection device on conduction, the oxide will by changing the volume features which seriously affect the response of sensor. In addition, the stress in the thin film sensor can reduce reaction or serious damage to the structure of sensor, which will only on the material into a small impact. Therefore, must overcome sensor technology appeared in the process of miniaturization of these new technology challenges.