基于超材料吸波结构的MEMS热电堆红外温度传感器设计

Design of MEMS Thermopile Infrared Temperature Sensor Based on Metamaterial Absorbing Structure

提出了一种基于超材料吸波结构的MEMS热电堆红外温度传感器,避免了使用特殊的滤光片进行封装,从而降低了传感器的体积。在设计上,采用超材料吸波结构将待测目标辐射的红外光选择性吸收,并将光能转化为热。通过利用时域有限差分方法研究了超材料吸波结构的结构参数与红外吸收光谱和吸收率之间的关系,并优化出用于检测人体红外辐射的超材料吸波结构尺寸。结果表明,当红外光波长范围为9.5μm~10.5μm时,该传感器的红外吸收率优于0.38,其中在波长为9.989μm处出现红外吸收峰,其最大吸收值为0.997。由超材料吸波结构产生的热量传递到其下方的热电堆,通过多物理场仿真可得热电堆的热端和冷端的温差为0.046 K,进而转化为输出电压,从而验证了整体设计的有效性。

A MEMS thermopile infrared temperature sensor based on the metamaterial absorbing structure is proposed,which avoids the use of special filters for packaging and reduces the volume of the sensor.In terms of design,the metamaterial absorbing structure is used to selectively absorb the infrared radiation of the target under test,and then converts infrared light energy into heat.The relationships between structural parameters of the metamaterial absorbing structure and the wavelength along with absorption rate of the infrared light are studied by using the finite difference time domain method,and the size of the metamaterial absorbing structure for detecting the infrared wavelength range of human radiation is optimized.The results indicate that when the wavelength range of infrared light is between 9.5μm-10.5μm,the infrared absorption rate of the sensor is better than 0.38,with an infrared absorption peak wavelength of 9.989μm and a maximum absorption value of 0.997.The heat generated by the metamaterial absorbing structure is transferred to the thermopile.Through multi-physics field simulation,the temperature difference between the hot and cold ends of the thermopile is simulated to be 0.046 K,which is then converted into output voltage,thus verifying the effectiveness of the overall design.