Design Rules of Bidirectional Smart Sensor Coating for Condition Monitoring of Bearings

Abstract

This paper reports a novel monitoring technique of bearings’ bidirectional load (axial and radial) based on a smart sensor coating, which is screen printed onto the surface of a cross-shaped steel substrate. To ensure the accuracy and stability of measurement as well as the durability of the printed coating, the developed prototype is built according to design rules commonly used in electronic circuits. The finite element model (FEM) is used to predict the mechanical property of the tested substrate under either unidirectional or bidirectional loads. Regarding the output voltage of the piezoelectric sensor, experimental results are revealed to be well-corelated to the numerical simulation. It is pointed out that the output signal generated from the sensor (electrode) could be particularly affected due to the capacitive parasite coming from the conductive tracks (CTs). Such a phenomenon might be reduced by printing them on the dielectric layer rather than on the piezocomposite layer. The study also investigates a highly anisotropic shape of electrodes (rectangular instead of circle), indicating that the orientation of such electrodes (axial or radial) does affect the output measurement. To sum up, the high performance of a sensor network coating depends not only on the ultimate characteristics of its own materials, but also on its structural design. Such an issue has been rarely reported on in the literature, but is nonetheless crucial to achieving reliable condition monitoring of bearings, especially for multidirectional loads—a key signature of early failure detection.

Haptic Feedback Device Using 3D-Printed Flexible, Multilayered Piezoelectric Coating for In-Car Touchscreen Interface

“…This study aimed to analyze the impact of electrodes on the actuation behavior of the piezoelectric wafer. In general, the electrodes should be as thin as possible to minimize their influence on the mechanical properties of the device [ 38 ]. However, they must also be good conductors and durable to withstand an important number of deformation cycles.…”

“…The piezoelectric sensing performance of BaTiO 3 -based devices, made with the same material and process as those conducted in this work, was determined in our recent research [ 38 , 76 ]. On the basis of the experimental characterizations, it was pointed out that the sensor exhibited a perfectly linear relationship between the output electrical signal and the input mechanical solicitation.…”

“…The distance between two successive pins is large enough (~2.54 mm) to avoid any electrical arc in case of high-voltage applications. The design of the CTs must fulfill the critical rules descried previously in [ 38 ] so as to reduce parasitic capacitance throughout empirical measurements. Noted that the printed sample is flexible enough to be foldable and stretchable, which is perfectly adequate in applications of haptic touchscreens.…”

“…The direct and inverse effects of the piezoelectric material make the design of haptic buttons quite ergonomic, compact, and multifunctional (i.e., able to perform in both sensor and actuator configurations). In addition, combining such a smart material design with 3D printing AM leads to an easier processing of multilayered architecture and overcomes critical issues imposed by the design rules of an electrical circuit [ 38 ].…”

Design Optimization of Printed Multi-Layered Electroactive Actuators Used for Steerable Guidewire in Micro-Invasive Surgery

“…Unfortunately, recent research suggests that the PE technologies remain underutilized in a large industrial scale [38][39][40] because of unpracticable and complex processes. Therefore, design for printed electronics (DfPE) is necessary to provide a framework that facilitates decision making as well as practical integration [41][42][43][44]. DfPE is a multifaceted field of study in which diverse topics such as mechanical and electrical engineering, materials science, optimization, and validation are all considered for enhancing PEs via holistic approaches [45][46][47][48].…”