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This paper aims at demonstrating the feasibility of a LoRaWAN-based sensor node for temperature monitoring, autonomously powered by a polycrystalline silicon photovoltaic module with possible applications within the Internet of Things (loT) domain in the horticulture field. The commercial solar cell was characterized under two light sources: a conventional white 4000 K Light Emitting Diode (LED) and a red and far red (R:FR) lamp peaked at 655 nm and 730 nm. The sensor node is equipped with a RFM95x LoRa transceiver which proved to be a valid technology in those application scenarios where robustness and low power consumption are required. The energy harvesting features are performed by a nano-power boost charger buck converter which deals with the power extraction from the photovoltaic module, the LiPo battery charging/discharging management and the supply of the sensor node. Field tests demonstrate that under R:fr light source, the energy self-sufficiency of the system is achieved: a positive balance between the battery charge and discharge is measured, sufficient both for the node working operation and for the battery charging.

In this work the feasibility of a NO 2 detection system based on photoacoustic effect is presented. The developed system takes advantage of low-cost components such as a commercial UV-LED as excitation source and a MEMS microphone as acoustic transducer. A cylindrical shaped structure has been used as a photoacoustic resonant cell and the light source modulated near its acoustic resonance frequency. Acoustic simulations have been carried out to investigate the acoustic coupling between the considered medium and the mechanical structure, and to determine the requirements of the readout electronic system. Preliminary gas measurement results are shown, obtained by exploiting an ad hoc realized characterization system. The gas sensing performances of the system have been tested in the range 0-50 ppm of NO 2 concentration.

Long Range (LoRa) has rapidly become one of the most widespread transmission technologies for the development of distributed monitoring systems for a wide range of applications within the Internet of Things (IoT) framework. Indeed, thanks to its robustness and high performances in terms of low power consumption and long transmission range, it has been employed in a wide range of critical application scenarios. In this context, this paper analyses the usability of LoRa as solution for data transmission in icy environments. While the technical feasibility of radio transmission channel in ice has been widely demonstrated, this paper aims at demonstrating the effectiveness of a low cost transmitter developed using off-the-shelf components, when completely immersed in ice. Fields tests were performed by embedding a Low Power Wide Area Network (LoRaWAN) compliant node inside a 10 cm block of dry ice, positioned then in an environmental chamber, at a −10°C temperature. Preliminary tests demonstrate the operation of the transmitter in these operating conditions, while the achieved link margin suggests the usability of this technology even in case of notably thicker layers of ice.

We discuss the design of an area-efficient CMOS analog core-cell implementing a PUF derived from a two-neurons Cellular Neural Network (CNN). The study is based on both theoretical modeling and numerical simulations, proposing circuit solutions in which the area consumption is strongly reduced by eliminating state capacitors and relying on distributed parasitic capacitances only.

The use of drones and unmanned aerial vehicles for monitoring infrastructures to guarantee safety and security is day by day more important. The possibility of a complete autonomous system for this kind of applications, in which drones can accomplish tasks 24 hours a day, seven days a week, without human intervention, is becoming a realistic scenario. From this standpoint a challenging issue is the automatic drone-batteries recharging and condition monitoring. In this article the authors present the solution adopted in a prototype drone hangar, able to manage up to 4 independent drones, that was developed with the support of the Italian Railway System (RFI).

We introduce a new method for the design of information entropy sources in Programmable Logic Devices (PLDs), based on a novel class of circuits called Digital Nonlinear Oscillators (DNOs) supporting complex dynamics, including chaos. Following this method, we designed a fully digital entropy source, i.e. entirely described in VHDL. The solution has been implemented on a Xilinx FPGA, showing, according to some tuning, periodic and chaotic behaviors.

In this paper the efficiency of carbonic anhydrase (CA) enzyme in accelerating the hydration of CO 2 is evaluated using a measurement system which consists of a vessel in which a gaseous flow of mixture of air and a fixed concentration of CO 2 (20%) is bubbled into a water solution containing a known quantity of CA enzyme. The pH value of the solution and the CO 2 concentration at the measurement system gas exhaust are continuously monitored. The measured CO 2 concentration allows for assessing the quantity of CO 2 , which is subtracted from the gaseous phase, dissolved into the liquid phase and/or hydrated. The measurement procedure consists of inducing a transient, and observing and modeling the different kinetics involved in the recovery of the steady state with and without CA.

This paper shows the feasibility of a High Frequency RFID passive sensor tag equipped with a novel humidity sensor based on a Si substrate, properly functionalized with a solution of nanoparticles of TiO 2 in order to increase its sensitivity. The characterization of the sensor is performed at variable humidity and using a properly designed front-end circuit. The reading circuit employed in the final prototype is tailored on the energy harvesting requirement. The obtained results prove that the solution conceived is satisfactory and that the sensor has good sensing properties in a large humidity range. The proposed system can be applied in the IoT framework in manifold monitoring scenarios, especially in humidity and soil moisture applications.

In this paper a smart measurement system is designed in order to monitor the thickness changes in a braking material of an electrodynamic structure (brake) exploited in tractors and ships. The same braking material can behave differently depending on different working conditions and often not easy inspection operations are required to monitor thickness changes of about 10-20µm. Safety and reliability implications arises as consequences of undesired wear-out rate. This work aims at the demonstration of the possibility to implement a trustable measurement system for aging effect monitoring of braking surfaces after heavy and variable load operations. A full material characterization has been performed to verify ideal starting conditions matching and maximum endurance of the selected braking material.

In this work we present a wearable, low-cost, low power device able to monitor health risks due to exposure to vibration of the hand-arm system, according to the ISO 5349–1 standard. The device is based on a small printed circuit board (‘sensing board’), which can be embedded in a glove and contains two tri-axial MEMS accelerometers with different characteristics. The sensing board ensures a large measurement range, it is powered by a battery allowing 8 hours operations, and transmits measurement data via Bluetooth. This wearable device is connected to a ‘base unit’, attached with a belt at the waist of the operatorthat can store data, generate alarms and/or transmit them with a radio-interface. This paper discusses also the impact on measurement accuracy of the design choices needed to obtain a wearable device. In particular, the effects of sensors positioning and mounting were studied in the frequency domain.

This paper shows the feasibility of a novel humidity sensor based on a low frequency micromachined electromechanical resonator functionalized with nanoparticles of TiO 2 . Immunity to the non-idealities of the conditioning electronic components was obtained by means of a low frequency resonator. In addition, this method was also applied in order to minimize the degradation of the resonator quality due to the deposition of the sensing material. The experimental results obtained using an ad-hoc characterization system show that this solution is viable and that the sensor has satisfactory performance in a large humidity range. It is worth noting that the proposed system can be used for structural health monitoring and novel measurements architecture.

This paper considers the current mode CMOS circuit implementation of the Sawtooth Piecewise Linear chaotic map. Starting from circuit analysis, we discuss a theoretical model to investigate the effects on the dynamical system entropy caused by the map shape nonlinear distortion, introduced by the circuit implementation. The results offer the designer an investigation tool to properly manage some relevant trade-offs related to the CMOS circuit design, highlighting the most critical model parameters affecting the deterioration of the achievable system entropy.