基于VO2热致相变的量热式生物传感器设计

Design of calorimetric biosensor based on VO2 thermally induced phase transition

本文基于VO2的热致相变特性,设计出由石墨烯、VO2、Si3N4等组成的微桥结构量热式生物传感器,优化了传感器的结构参数,研究了传感器的热学、力学和电学性能。通过理论计算和仿真分析得出量热式生物传感器的热导为5.4×10^-7 W/K,热时间常数为12 ms,最大位移形变和最大等效应力分别为2.3×10^-9μm和1.57×10^-5 MPa。运用Comsol软件对量热式生物传感器进行热电耦合分析,计算了在不同环境温度和电流密度下传感器对微弱热信号的温度电压响应特性,结果表明:在室温工作环境下,传感器的有效热响应时间为7 ms,电阻温度系数为-0.0276 K^-1,最小温度分辨率为0.061℃,该传感器具有良好的热学和力学性能,对微弱热信号具有较好的线性响应特性。

In this work,a calorimetric biosensor with microbridge structure was designed based on VO2 thermochromic phase transition characteristics.This biosensor was made up of grapheme,VO2 and Si3N4.The thermal,mechanical and electrical properties of the sensor were investigated.Through theoretical calculation and simulation analysis,it is concluded that the thermal conductivity of the calorimetric biosensor is 5.4×10^-7 W/K,the thermal time constant is 12 ms,and the maximum displacement deformation and the maximum equivalent stress are 2.3×10^-9μm and 1.57×10^-5 MPa,respectively.Comsol software was used to conduct the thermoelectric coupling analysis and calculate the responsive characteristics between the voltage and temperature under different temperatures and current densities.At room temperature,the effective thermal response time of the sensor is 7 ms,and the resistance temperature coefficient and the miximum temperature resolution are-0.0276 K-1 and 0.061℃,respectively.The results show that the sensor has good thermal and mechanical properties as well as linear response characteristics to weak thermal signals.