Design and Evaluation of a Multidirectional Thermal Flow Sensor on Flexible Substrate

Abstract EN

The development and the corresponding evaluation of a multidirectional thermal flow sensor are presented in this work.

The sensor was fabricated on a flexible substrate, allowing for new applications, since it provides the possibility of installation in nonplanar surfaces such as pipelines.

Furthermore, the sensing elements are not in direct contact with the fluid, which increases the device reliability, extends its application range, and allows the noncontact monitoring of fluids.

This was achieved by utilizing the substrate as a protective layer between the sensing elements and the fluid under measurement.

The operation principle is based on the determination of the flow-induced temperature profile variations.

A dedicated experimental setup was designed and used for the device evaluation.

Both flow velocity value and direction were successfully extracted, while the results were consistent with the predicted theoretical values.

A single-layer back propagation neural network that correlates the sensors’ readouts to the angle of rotation was implemented, which leads to a mean absolute direction estimation error in the order of 2.7 degrees independent to the training procedure datasets.