More than a decade of research in the field of thermal, motion, vibration and electromagnetic radiation energy harvesting has yielded increasing power output and smaller embodiments. Power management circuits for rectification and DC-DC conversion are becoming able to efficiently convert the power from these energy harvesters. This paper summarizes recent energy harvesting results and their power management circuits.

Micropower energy harvesting

The idea of the Internet of Things (IOT) notion is that everything within the global network is accessible and interconnected. As such Wireless Sensor Networks (WSN) play a vital role in such an environment, since they cover a wide application field. Such interconnection can be seen from the aspect of a remote user who can access a single desired sensor node from the WSN without the necessity of firstly connecting with a gateway node (GWN). This paper focuses on such an environment and proposes a novel user authentication and key agreement scheme for heterogeneous ad hoc wireless sensor networks. The proposed scheme enables a remote user to securely negotiate a session key with a general sensor node, using a lightweight key agreement protocol. The proposed scheme ensures mutual authentication between the user, sensor node, and the gateway node (GWN), although the GWN is never contacted by the user. The proposed scheme has been adapted to the resource-constrained architecture of the WSN, thus it uses only simple hash and XOR computations. Our proposed scheme tackles these risks and the challenges posed by the IOT, by ensuring high security and performance features.

A novel user authentication and key agreement scheme for heterogeneous ad hoc wireless sensor networks, based on the Internet of Things notion

The concept of Internet of Things (IOT), which is already at our front doors, is that every object in the Internet infrastructure (II) is interconnected into a global dynamic expanding network. Sensors and smart objects are beside classical computing devices key parties of the IOT. We can already exploit the benefits of the IOT by using various weareables or smart phones which are full of diverse sensors and actuators and are connected to the II via GPRS or Wi-Fi. Since sensors are a key part of IOT, thus are wireless sensor networks (WSN). Researchers are already working on new techniques and efficient approaches on how to integrate WSN better into the IOT environment. One aspect of it is the security aspect of the integration. Recently, Turkanovic et?al.'s proposed a highly efficient and novel user authentication and key agreement scheme (UAKAS) for heterogeneous WSN (HWSN) which was adapted to the IOT notion. Their scheme presented a novel approach where a user from the IOT can authenticate with a specific sensor node from the HWSN without having to communicate with a gateway node. Moreover their scheme is highly efficient since it is based on a simple symmetric cryptosystem. Unfortunately we have found that Turkanovic et?al.'s scheme has some security shortcomings and is susceptible to some cryptographic attacks. This paper focuses on overcoming the security weaknesses of Turkanovic et?al.'s scheme, by proposing a new and improved UAKAS. The proposed scheme enables the same functionality but improves the security level and enables the HWSN to dynamically grow without influencing any party involved in the UAKAS. The results of security analysis by BAN-logic and AVISPA tools confirm the security properties of the proposed scheme.

An efficient user authentication and key agreement scheme for heterogeneous wireless sensor network tailored for the Internet of Things environment

Modern gas monitoring scenarios for medical diagnostics, environmental surveillance, industrial safety, and other applications demand new sensing capabilities. This Review provides analysis of development of new generation of gas sensors based on the multivariable response principles. Design criteria of these individual sensors involve a sensing material with multiresponse mechanisms to different gases and a multivariable transducer with independent outputs to recognize these different gas responses. These new sensors quantify individual components in mixtures, reject interferences, and offer more stable response over sensor arrays. Such performance is attractive when selectivity advantages of classic gas chromatography, ion mobility, and mass spectrometry instruments are canceled by requirements for no consumables, low power, low cost, and unobtrusive form factors for Internet of Things, Industrial Internet, and other applications. This Review is concluded with a perspective for future needs in fundament...

Multivariable Sensors for Ubiquitous Monitoring of Gases in the Era of Internet of Things and Industrial Internet

Breath sensors can revolutionize medical diagnostics by on-demand detection and monitoring of health parameters in a noninvasive and personalized fashion. Despite extensive research for more than two decades, however, only a few breath sensors have been translated into clinical practice. Actually, most never even left the scientific laboratories. Here, we describe key challenges that currently impede realization of breath sensors and highlight strategies to overcome them. Specifically, we start with breath marker selection (with emphasis on metabolic and inflammatory markers) and breath sampling. Next, the sensitivity, stability, and selectivity requirements for breath sensors are described. Concepts are elaborated to systematically address these requirements by material design (focusing on chemoresistive metal oxides), orthogonal arrays, and filters. Finally, aspects of portable device integration, user communication, and clinical applicability are discussed.

Breath Sensors for Health Monitoring

a b s t r a c t This paper describes the development and the characterization of a wireless gas sensor network (WGSN) for the detection of combustible or explosive gases. The WGSN consists of a sensor node, a relay node, a network coordinator, and a wireless actuator. The sensor node attains early gas detection using an on board 2D semiconductor sensor. Because the sensor consumes a substantial amount of power, which negatively affects the node lifetime, we employ a pulse heating profile to achieve significant energy savings. The relay node receives and forwards traffic from sensor nodes towards the network coordinator and vice versa. When an emergency is detected, the network coordinator alarms an operator through the GSM/GPRS or Ethernet network, and may autonomously control the source of gas emission through the wireless actuator. Our experimental results demonstrate how to determine the optimal temperature of the sensor's sensitive layer for methane detection, show the response time of the sensor to various gases, and evaluate the power consumption of the sensor node. The demonstrated WGSN could be used for a wide range of gas monitoring applications.

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Development of wireless sensor network for combustible gas monitoring

Wireless sensor networks (WSN) have been adopted in various monitoring applications. However, due to the high power consumption of catalytic gas sensors, which enable reliable gas detection, there is a lack of real WSN deployments aimed at the monitoring of combustible gases. This work reports on the evaluation of a WSN deployed in a real operational boiler facility. The WSN consists of nine battery-powered wireless sensor nodes (with an onboard catalytic sensor) controlled by a network coordinator. In this safety critical environment our objective is twofold: (i) guarantee precise and fast sensor response, and (ii) deliver the sensed data from the sensor nodes to the network coordinator safely in case of methane leakage. We first describe the deployment of the WSN and then evaluate the catalytic sensor response under various conditions. Besides, we evaluate the wireless links using the received signal strength indicator (RSSI) and link quality indicator (LQI) metrics. Finally, the experimental results demonstrate that during 5 months of deployment the sensor nodes have been discharged for 22–27%.

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Deployment and evaluation of a wireless sensor network for methane leak detection

The Wireless Sensor Network (WSN) technology has recently been used, rather successfully, in a huge number of monitoring applications. However, the monitoring of combustible gases with WSN stands out from typical applications where the wireless communications function is much more power hungry than the sensing one. The reason behind this “dissonance” is in using catalytic or semiconductor sensors that ensure a trade-off among the safety requirements, performance and power consumption. This work provides a survey of intrinsic power optimization techniques with a special focus on recent advances in power management, sensor fabrication, sensing circuits, and measurement procedures. The paper concludes with providing a future outlook in the area.

Optimization of power consumption for gas sensor nodes: A survey

Wireless Sensors Networks (WSN) have recently been applied in a number of hazardous gas detection applications. The state-of-the-art works make an emphasis on sensing and delivering of alert message over the WSN to an operator. Instead, in this paper, we propose a wireless sensor–actuator system which aims at quick gas detection and immediate isolation of gas leak source. The low power wireless sensor node includes catalytic gas sensors, micro processing unit and wireless transceiver which communicates with wireless actuator using ZigBee/IEEE802.15.4 standard and BACnet protocol. Wireless actuator consists of power management circuit, micro processing unit and gas valve. The experimental results demonstrate the sensor node long lifetime while fulfilling performance requirements, quick detection of a hazardous gas and fast actuation time.

/pdf/a-wireless-sensor-actuator-system-for-hazardous-gases-6q32rrxgns.pdf

A wireless sensor-actuator system for hazardous gases detection and control

Wireless sensor networks (WSNs) have recently been applied for industrial monitoring, including combustible and flammable gases monitoring. In this work, we present a wireless gas sensor node in which a widely used Wheatstone sensing circuit based on two sensors is exchanged with a single sensor circuit, as well as the associate gas measurement procedure. The core of the measurement procedure is the four-stage heating profile, which enables low power consumption of sensing circuit and thermo compensation adjustment. A thermo compensation algorithm is capable of avoiding the effect of the environmental temperature on the measurements by keeping stable zero-offset within $\pm 1\;\hbox{mV}$ and ensuring low absolute error within 0.1% vol. The thorough design of the sensor node allows it to fit into the $5.5\;{\hbox{cm}^3}$ packaging, which ensures its true ubiquitous deployment in outdoor and industrial environment.

/pdf/compact-low-power-wireless-gas-sensor-node-with-thermo-3q1c3esgm0.pdf

Denis Spirjakin

Papers

Development of wireless sensor network for combustible gas monitoring

Deployment and evaluation of a wireless sensor network for methane leak detection

Optimization of power consumption for gas sensor nodes: A survey

A wireless sensor-actuator system for hazardous gases detection and control

Compact Low Power Wireless Gas Sensor Node With Thermo Compensation for Ubiquitous Deployment