Flexible Integration of Alternative Energy Sources for Autonomous Sensing

Recent developments in energy harvesting and autonomous sensing mean that it is now possible to power sensors solely from energy harvested from the environment. Clearly this is dependent on sufficient environmental energy being present. The range of feasible environments for operation can be extended by combining multiple energy sources on a sensor node. The effective monitoring of their energy resources is also important to deliver sustained and effective operation. This paper outlines the issues concerned with combining and managing multiple energy sources on sensor nodes. This problem is approached from both a hardware and embedded software viewpoint. A complete system is described in which energy is harvested from both light and vibration, stored in a common energy store, and interrogated and managed by the node

Flexible integration of alternative energy sources for autonomous sensing

Recent developments in energy harvesting and autonomous sensing mean that it is now possible to power sensors solely from energy harvested from the environment. Clearly this is dependent on sufficient environmental energy being present. The range of feasible environments for operation can be extended by combining multiple energy sources on a sensor node. The effective monitoring of their energy resources is also important to deliver sustained and effective operation. This paper outlines the issues concerned with combining and managing multiple energy sources on sensor nodes. This problem is approached from both a hardware and embedded software viewpoint. A complete system is described in which energy is harvested from both light and vibration, stored in a common energy store, and interrogated and managed by the node

A TEG-excited switched reluctance generator for self-powered sensing in next generation aircraft

New aircraft concepts are proposed to support emission reduction in aviation. To achieve the advantages of these concepts an electrical system with high power delivery and low system mass needs to be considered. The reduction of weight of all sub-components without compromising on reliability is being investigated. To achieve these self-powered systems can be introduced to monitor safety critical components. Locally embedded wireless self-powered systems can reduce the weight associated with health monitoring significantly compared to wired systems. In this paper a self-powered system that can be embedded in the engine is introduced. Switched reluctance generator integrated with a thermoelectric generator (TEG) is designed to provide power for bearing health monitoring. An efficient switched reluctance generator is designed for the limited amount of space in the aircraft engine. Two configurations for a six stator poles and fifteen rotor poles (6/15), three phase switched reluctance generator were compared and highest power output was obtained when the individual phase coils were connected in parallel. To achieve efficient energy conversion, the design process and selection of the excitation and generation angles played an important role

Energy Neutral Activity Monitoring:Wearables Powered by Smart Inductive Charging Surfaces

Wearable technologies play a key role in the shift of traditional healthcare services towards eHealth and self-monitoring. Maintenance overheads, such as regular battery recharging, impose a limitation on the applicability of such technologies in some groups of the population. In this paper, we propose an activity monitoring system that is based on wearable sensors that are powered by textile inductive charging surfaces. By strategically positioning these surfaces on pieces of furniture that are routinely used, the system passively charges the wearable sensor whilst the user is present. As a proof-of-concept example, experiments conducted on a prototype implementation of the system suggest that 36 minutes of daily desktop computer usage are on average sufficient to maintain a wearable sensor energy neutral

Effects of the binder material on the mechanical properties of thick-film magnetostrictive materials

This paper presents research carried out at the University of Southampton into the development of a magnetostrictive thick-film material suitable for use with silicon micromachined devices. This form of magnetostrictive material has previously been deposited onto alumina substrates and this paper reports further work on migrating the technology onto silicon. The evaluation of two alternative glass frits for use as the binder within the thick film is reported. The correct choice of the binder material is important in a thick-film material because it is responsible for binding the active material within the thick film into a composite material and also adhering the film to the substrate. A series of tests have been applied to samples fabricated using various glass frits to assess their mechanical properties and suitability for the micro-actuator applications

Thick-Film Actuation Technologies For MEMS Applications

This paper compares two thick-film actuation technologies and assesses their suitability for use within micromachined devices. The materials are a piezoelectric composition, which exhibits a d33 coefficient of the order of 130pC/N, and a magnetostrictive material which possess a magnetostriction of 4.4ppm at a magnetic field of 11.5kA/m. Examples of their application in micromachined devices are also given

Modular Plug-and-Play Power Resources for Energy-Aware Wireless Sensor Nodes

Wireless sensors are normally powered by non-rechargeable batteries, but these must be replaced when depleted. Recent developments in energy harvesting technology allow sensors to be powered by environmental energy where it is present, but the wide range of situations where sensors are deployed means that it is desirable for the energy components of a sensor node (i.e. batteries, supercapacitors, and power generation devices) to be selected and configured at the time of node deployment. Previous energy harvesting-powered systems have been designed for specific energy hardware and been difficult to adapt for different resources. Energy-awareness is useful for state-of-the-art network algorithms, but present systems do not provide a standardized or straightforward way for nodes to monitor and manage their energy hardware. The developments reported in this paper deliver a reconfigurable energy subsystem for wireless autonomous sensors. The new system permits energy modules to be selected and fitted to the sensor node in-situ, in a plug-and-play manner, without the need for reprogramming or the modification of hardware. The node can monitor and intelligently manage its energy resources and assess its overall energy status by analyzing its level of stored energy and rate of power generation. These activities are facilitated by a proposed common hardware interface (which allows multiple energy modules to be connected) and an electronic datasheet structure for the energy modules. The system has been verified through the development and testing of a prototype wireless sensor node which operates from a mix of energy sources