This review presents the state of the art of the application of energy harvesting in commercial and residential buildings. Electromagnetic (optical and radio frequency), kinetic, thermal and airflow-based energy sources are identified as potential energy sources within buildings and the available energy is measured in a range of buildings. Suitable energy harvesters are discussed and the available and the potential harvested energy calculated. Calculations based on these measurements, and the technical specifications of state-of-the-art harvesters, show that typical harvested powers are: (1) indoor solar cell (active area of 9 cm2, volume of 2.88 cm3): ∼300 µW from a light intensity of 1000 lx; (2) thermoelectric harvester (volume of 1.4 cm3): 6 mW from a thermal gradient of 25 °C; (3) periodic kinetic energy harvester (volume of 0.15 cm3): 2 µW from a vibration acceleration of 0.25 m s−2 at 45 Hz; (4) electromagnetic wave harvester (13 cm antenna length and conversion efficiency of 0.7): 1 µW with an RF source power of −25 dBm; and (5) airflow harvester (wind turbine blade of 6 cm diameter and generator efficiency of 0.41): 140 mW from an airflow of 8 m s−1. These results highlight the high potential of energy harvesting technology in buildings and the relative attractions of various harvester technologies. The harvested power could either be used to replace batteries or to prolong the life of rechargeable batteries for low-power (∼1 mW) electronic devices.

No abstract

This paper presents research into a user-friendly electronic sleeve (e-sleeve) with integrated electrodes in an array for wearable healthcare. The electrode array was directly printed onto an everyday clothing fabric using screen printing. The fabric properties and designed structures of the e-sleeve were assessed and refined through interaction with end users. Different electrode array layouts were fabricated to optimize the user experience in terms of comfort, effectivity and ease of use. The e-sleeve uses dry electrodes to facilitate ease of use and the electrode array can survive bending a sufficient number of times to ensure an acceptable usage lifetime. Different cleaning methods (washing and wiping) have been identified to enable reuse of the e-sleeve after contamination during use. The application of the e-sleeve has been demonstrated via muscle stimulation on the upper limb to achieve functional tasks (e.g., hand opening, pointing) for eight stroke survivors.

This paper presents a comprehensive evaluation of fabrication techniques for the integration of coils into textiles, for the purpose of enabling low-power wireless power transfer; for example, the powering of on-body monitoring devices, such as heart-rate monitors. Key electrical parameters of the coils required to maximize power transfer efficiency are identified from theory. Flexible coils have been fabricated using standard processes widely used in the textile industry, such as screen printing and embroidery. The screen printed coils were fabricated with a silver-polymer ink on a printed interface layer; the embroidered coils were fabricated using a variety of conductive threads formed by coating textile fibers and through the use of copper fibers. These coils have been experimentally characterized and evaluated for use in wireless power transfer applications. The effects of coil geometry and separation on the dc-dc power transfer efficiency using Qi standard compliant driver and receiver circuits are reported.

Globally, human life expectancy is steadily increasing causing an increase in the elderly population and consequently increased costs of supporting them. Ambient assisted living is an active research area aimed at supporting elderly people to live independently in their preferred living environment. This paper presents the design and testing of a self-powered wearable headband for electroencephalogram (EEG) based detection of emotions allowing the evaluation of the quality of life of assisted people. Printed active electrode fabrication and testing is discussed followed by the design of an energy harvester for powering the headband. The results show that the fabricated electrodes have similar performance to commercial electrodes and that the electronics embedded into the headband, as well as the wireless sensor node used for processing the EEG, can be powered by energy harvested from solar panels integrated on the headband. An average real time emotion classification accuracy of 90 (±9) % was obtained from 12 subjects. The results show that the self-powered wearable headband presented in this paper can be used to measure the wellbeing of assisted people with good accuracy.