**8. Conclusion**

*Perovskite and Piezoelectric Materials*

health, logistics, and intelligent transport.

firefighting in marine applications.

of a canoe rescue in bad weather.

network on board ships.

**7. Application of the sensor for marine fire detection**

In terms of application areas, sensor networks have a potential that is revolving around many sectors of our economy and our daily lives; from environmental monitoring and preservation to industrial manufacturing, automation in the transport and health sectors, and the modernization of medicine, agriculture, telematics, and logistics. This new technology promises to revolutionize the way we live, work, and interact with the physical environment around us. Wirelessly communicating sensors with computing capabilities facilitate a series of applications that were impossible or too expensive a few years ago. Today, these tiny and inexpensive devices can be literally scattered over roads, structures, walls, or machines, capable of detecting a variety of physical phenomena. Many fields of application are then considered, such as disaster detection and monitoring, environmental monitoring and biodiversity mapping, intelligent buildings, precision agriculture, machine monitoring and preventive maintenance, medicine and

Today, the use of these sensors is increasingly required for supervision and safety. Industrial companies then propose wireless sensors that can inform the user about the evolution of different physical quantities, so they constitute a very fertile research axis. In addition, the development of temperature sensors has several advantages, the most important of which is safety. The current trend, given the new applications that are emerging, is to oversize sensors and make them compatible with signal processing systems in order to obtain fully integrated systems. Environmental objectives and firefighting are the most targeted applications today. The lists of applications (safety, control, analysis, comfort, etc.) and fields of application (environment, safety, medical, automotive, home automation, etc.) are very long, reflecting the great interest in the development of temperature sensors. The development of these systems generally includes a miniature, low-cost, and high-performance sensor. This is what drives our current research. Indeed, miniaturization is important to be able to easily embed autonomous systems that are increasingly distributed in networks. The cost price is of course an important factor and will be decisive for the marketing development of these sensors. The quest for performance is to make the information obtained by these sensors more reliable and affordable. This is practically interesting for the intended application: improving

Obviously, of all the disasters that can happen to a ship, fire is certainly the most horrible. Ashore, occupants of burning buildings can rely on fire pumps and ladders that can be on site within minutes of the first alarm signal. A ship at sea, on the other hand, must rely solely on itself in fighting the fire as in everything else, and from the first fire signal to retirement or hard-won victory, there may be no chance

The consequences of a fire on board a ship are always costly and sometimes tragic. It is therefore essential to have effective firefighting systems, but it is now known that conventional temperature sensors, which were widely used in the past, have significant disadvantages. The present system aims to solve this problem by using simple, autonomous, and inexpensive means. As a result, this design greatly reduces the overall energy consumption of the temperature sensor

To effectively control ship temperature, the use of this passive temperature sensor makes it possible to keep an eye on the temperature at all times, for long periods of time, and to alert staff in the event of a problem. If the temperature in a monitoring zone suddenly exceeds the threshold value, the sensor detects it in real time and transmits the information to the supervisor for intervention. This avoids

**168**

The results presented in this chapter are very encouraging: the simulation of a passive temperature sensor based on an electromagnetic transduction gave very good performances. These simulation results obtained, using previous work, allow us to consider the realization of a new high-performance temperature sensor. The optimization of this type of device was done using global electromagnetic simulations on HFSSTM including all system elements. The combination of PLZT material, dielectric resonator, and coplanar lines makes it possible to produce a narrowband filter that we excite with an electromagnetic wave at microwaves in gallery modes.

The key point of our application is based on the performance of the perovskite material and the properties of the RD gallery modes. Indeed, the dielectric resonator, covered with the sensitive material, is excited in a gallery mode that allows its oversizing with millimeter waves and its association with transmission lines in order to have a band-pass directional filter. Thus, we designed the entire 3D device on HFSS™. This software has the advantage of being rigorous and allows, a priori, taking into account all the physical and geometric characteristics of the device.

In the second part of this chapter, we have presented some of the results obtained. Several gallery modes have been observed over a wide frequency band; the Ka-band. We have therefore shown through these simulations that the measurement of the resonance frequency of a gallery mode in the dielectric resonator translates, in principle, a temperature variation with a remarkable sensitivity.

The implementation of such a device, which offers passive temperature detection, makes it possible to consider the design of a temperature sensor with high sensitivity electromagnetic transduction. The characterization of such a sensor makes it possible to evaluate the frequency in terms of geometric dispersions such as the influence of material thicknesses, and diameters will be presented in the next chapter.

Finally, our contribution provides innovative technology to meet the need to improve fire protection in maritime transport. Temperature control and traceability still require manual procedures dependent on onboard energy. The proposed system simplifies and automates relatively all these manual interventions and particularly does not require any onboard power supply. Thereafter, this firefighting device has a sensitivity of about 10 MHz/°C and allows the temperature to be controlled at any time and to react quickly in the event of a problem.

*Perovskite and Piezoelectric Materials*
