Articles techniques et présentations

This paper presents the design and simulation of novel micrometer-scale capacitive temperature sensors, which could serve as a component for miniaturized wireless sensor nodes for the internet of things requiring structural flexibility and optical transparency. The proposed sensor design employs a conventional, planar interdigitated capacitor structure, explores the thermo-mechanical property (thermal expansion coefficient) of various sensing materials including a conductive polymer, and can be easily implemented using double-layer surface micromachining process. The operating characteristics of prototype sensors comprising different sensing electrodes are investigated as a function of various physical design parameters using COMSOL Multiphysics® software. Electromechanics Physics Interface was employed for modeling. FEM simulation results show that the prototype sensor that utilizes a conductive polymer for the sensing electrode exhibits a reasonably good linearity and sensitivity (~0.31 fF/˚C) over a relatively wide temperature range (between 7 and 127 ˚C). The dimensions and electrode materials (e.g., Au, Cr and W) of the proposed sensor can be readily customized for different temperature ranges required for different applications.