Everyday tasks use sensors to monitor and provide information about processes in different scenarios, such as monitoring devices in manufacturing or homes. Sensors need to communicate, with or without wires, while providing secure information. Power can be derived from various energy sources, such as batteries, electrical power grids, and energy harvesting. Energy harvesting is a promising way to provide a sustainable and renewable source to power sensors by scavenging and converting energy from ambient energy sources. However, low energy is harvested through these methods. Therefore, it is becoming a challenge to design and deploy wireless sensor networks while ensuring the sensors have enough power to perform their tasks and communicate with each other through careful management and optimization, matching energy supply with demand. For this reason, data cryptography and authentication are needed to protect sensor communication. This paper studies how energy harvested with microbial fuel cells can be employed in algorithms used in data protection during sensor communication.

In recent years, there has been an increasing necessity for monitoring facilities like gas or water pipelines in order to ensure high security and adequate infrastructure maintenance. The pipeline network is very large, and the main problem is its continuous monitoring. In particular, there is the necessity to monitor the cathodic protection voltage, which ensures maintaining the pipeline under a state of protection from corrosion and avoids considerable damage to the infrastructure. A communication channel is necessary to monitor the pipeline network continuously. Most of the pipeline monitoring systems make use of wireless communication, like GSM (Global System for Mobile Communications) or GPRS (General Packet Radio Service) technology and even Wi-Fi, to transmit the measurements. By their nature, the implementation of these systems is often expensive and furthermore, not all the pipeline is covered by the signals of the mobile operators. In this paper, the communication approach is presented, and in particular, the pipeline is used as a communication channel. Due to the challenges of pipelined transmission, an identification of the characteristic impedance of the medium must be conducted to obtain the best possible performance. This value is used to design a circuit that can match the function generator output to the impedance of the communication channel. The circuit to be made must allow bidirectional communication of the half-duplex type. Given the low frequencies that can be used for communication on the pipe, a low-frequency circulator must be created. Given the frequencies involved, the bidirectional circuit will be composed of operational amplifiers. The presented circulator allows matching the signal generator output impedance with the pipeline input impedance, in order to obtain an improvement in the transmission distance achievable using the pipeline as a communication channel.

Smart sensors and networks have spread worldwide over the past few decades. In the industry field, these concepts have found an increasing quantity of applications. The omnipresence of smart sensor networks and smart devices, especially in the industrial world, has contributed to the emergence of the concept of Industry 4.0. In a world where everything is interconnected, communication among smart devices is critical to technological development in the field of smart industry. To improve communication, many engineers and researchers implemented methods to standardize communication along the various levels of the ISO-OSI model, from hardware design to the implementation and standardization of different communication protocols. The objective of this paper is to study and implement an unconventional type of communication, exploiting acoustic wave propagation on metallic structures, starting from the state of the art, and highlighting the advantages and disadvantages found in existing literature, trying to overcome them and describing the progress beyond the state of the art. The proposed application for acoustic communication targets the field of smart industries, where implementing signal transmission via wireless or wired methods is challenging due to interference from the widespread presence of metallic structures. This study explores an innovative approach to acoustic communication, with a particular focus on the physical challenges related to acoustic wave propagation. Additionally, communication performance is examined in terms of noise rejection, analyzing the impact of injected acoustic noise on communication efficiency.