Open Access Open Access  Restricted Access Subscription or Fee Access

Aluminum Nitride High Temperature Strain Sensors

F. T. GOERICKE, A. P. PISANO

Abstract


Aluminum nitride is introduced as a promising material for high temperature resonating sensors. Two types of resonant strain sensors, double-ended tuning forks (DETFs) and triple-beam tuning forks (TBTFs), are discussed. The performance of the devices at elevated temperature up to 450 °C is investigated. By comparing the experimental results of TBTFs with and without a frame that can decouple substrate strains it is shown that the frequency shift upon heating is dominated by the coefficient of thermal expansion mismatch between the silicon substrate and the aluminum nitride device layer. It is demonstrated that these sensors can be employed with high accuracy for strain sensing at high temperature. A possible field of application for this technology is the structural health monitoring of industrial and building components exposed to harsh environment operating conditions or during catastrophes.

Full Text:

PDF