scholarly journals Estimation of kinetic energy harvesting potential for self-powered wearable devices with 67,000 participants from the UK Biobank

Author(s):  
Christopher Beach ◽  
Alex Casson

Energy harvesting from human motion can reduce reliance on battery recharging in wearable devices and lead to improved adherence. However, to date, studies estimating energy harvesting potential have largely focused on small scale, healthy, population groups in laboratory settings rather than free-living environments with population level participant numbers. Here, we present the largest scale investigation into energy harvesting potential by utilising the activity data collected in the UK Biobank from over 67,000 participants. This paper presents detailed stratification into how the day of the week and participant age affect harvesting potential, as well as how the presence of conditions (such as diabetes, which we investigate here), may affect the expected energy harvester output. We process accelerometery data using a kinetic energy harvester model to investigate power output at a high temporal resolution. Our results identify key differences between the times of day when the power is available and an inverse relationship between power output and participant age. We also identify that the presence of diabetes substantially reduces energy harvesting output, by over 21%. The results presented highlight a key challenge in wearable energy harvesting: that wearable devices aim to monitor health and wellness, and energy harvesting aims to make devices more energy autonomous, but the presence of medical conditions may lead to substantially lower energy harvesting potential. The findings indicate how it is challenging to meet the required power budget to monitor diseases when energy autonomy is a goal.

2021 ◽  
Author(s):  
Christopher Beach ◽  
Alex Casson

Energy harvesting from human motion can reduce reliance on battery recharging in wearable devices and lead to improved adherence. However, to date, studies estimating energy harvesting potential have largely focused on small scale, healthy, population groups in laboratory settings rather than free-living environments with population level participant numbers. Here, we present the largest scale investigation into energy harvesting potential by utilising the activity data collected in the UK Biobank from over 67,000 participants. This paper presents detailed stratification into how the day of the week and participant age affect harvesting potential, as well as how the presence of conditions (such as diabetes, which we investigate here), may affect the expected energy harvester output. We process accelerometery data using a kinetic energy harvester model to investigate power output at a high temporal resolution. Our results identify key differences between the times of day when the power is available and an inverse relationship between power output and participant age. We also identify that the presence of diabetes substantially reduces energy harvesting output, by over 21%. The results presented highlight a key challenge in wearable energy harvesting: that wearable devices aim to monitor health and wellness, and energy harvesting aims to make devices more energy autonomous, but the presence of medical conditions may lead to substantially lower energy harvesting potential. The findings indicate how it is challenging to meet the required power budget to monitor diseases when energy autonomy is a goal.


Author(s):  
Hieu Nguyen ◽  
Hamzeh Bardaweel

The work presented here investigates a unique design platform for multi-stable energy harvesting using only interaction between magnets. A solid cylindrical magnet is levitated between two stationary magnets. Peripheral magnets are positioned around the casing of the energy harvester to create multiple stable positions. Upon external vibration, kinetic energy is converted into electric energy that is extracted using a coil wrapped around the casing of the harvester. A prototype of the multi-stable energy harvester is fabricated. Monostable and bistable configurations are demonstrated and fully characterized in static and dynamic modes. Compared to traditional multi-stable designs the harvester introduced in this work is compact, occupies less volume, and does not require complex circuitry normally needed for multi-stable harvesters involving piezoelectric elements. At 2.5g [m/s2], results from experiment show that the bistable harvester does not outperform the monostable harvester. At this level of acceleration, the bistable harvester exhibits intrawell motion away from jump frequency. Chaotic motion is observed in the bistable harvester when excited close to jump frequency. Interwell motion that yields high displacement amplitudes and velocities is absent at this acceleration.


2016 ◽  
Vol 09 (05) ◽  
pp. 1650069 ◽  
Author(s):  
Yaoze Liu ◽  
Tongqing Yang ◽  
Fangming Shu

Since the piezoelectric properties were used for energy harvesting, almost all forms of energy harvester needs to be bonded with a mass block to achieve pre-stress. In this article, disc type piezoelectric energy harvester is chosen as the research object and the relationship between mass bonding area and power output is studied. It is found that if the bonding area is changed as curved, which is usually complanate in previous studies, the deformation of the circular piezoelectric ceramic is more uniform and the power output is enhanced. In order to test the change of the deformation, we spray several homocentric annular electrodes on the surface of a piece of bare piezoelectric ceramic and the output of each electrode is tested. Through this optimization method, the power output is enhanced to more than 11[Formula: see text]mW for a matching load about 24[Formula: see text]k[Formula: see text] and a tip mass of 30[Formula: see text]g at its resonant frequency of 139[Formula: see text]Hz.


Author(s):  
Davide Castagnetti

Energy harvesting from kinetic ambient energy requires converters able to efficiently operate in the low frequency range. A limit of the solutions proposed in the literature, both electromagnetic and piezoelectric, is their operating frequency, which generally ranges from about 50 to 300 Hz. To overcome these limitations, this work proposes an innovative energy harvester exploiting two counteracting Belleville springs. Thanks to the peculiar height to thickness ratio of the springs a highly compliant elastic system is obtained, which can be used either for electromagnetic or piezoelectric harvesting. The harvester is modelled analytically and numerically both with regard to the force-displacement and to the modal response. The experimental validation of the harvester, highlights a noticeable power output but at a higher eigenfrequency than expected.


Author(s):  
Abbas F. Jasim ◽  
Hao Wang ◽  
Greg Yesner ◽  
Ahmad Safari ◽  
Pat Szary

This study investigated the energy harvesting performance of a piezoelectric module in asphalt pavements through laboratory testing and multi-physics based simulation. The energy harvester module was assembled with layers of Bridge transducers and tested in the laboratory. A decoupled approach was used to study the interaction between the energy harvester and the surrounding pavement. The effects of embedment location, vehicle speed, and temperature on energy harvesting performance were investigated. The analysis findings indicate that the embedment location and vehicle speed affects the resulted power output of the piezoelectric energy harvesting system. The embedment depth of the energy module affects both the magnitude and frequency of stress pulse on top of the energy module induced by tire loading. On the other hand, higher vehicle speed causes greater loading frequency and thus greater power output; the effect of pavement temperature is negligible. The analysis of total power output before reaching fatigue failure of the energy module can be used to determine the optimum embedment location in the asphalt layer. The proposed energy harvesting system provides great potential to generate green energy from waste kinetic energy in roadway pavements. Field study is recommended to verify these findings with long-term performance monitoring of pavement with embedded energy harvesters.


2019 ◽  
Vol 30 (7) ◽  
pp. 998-1009 ◽  
Author(s):  
XF Zhang ◽  
HS Tzou

Based on the electromechanical coupling of piezoelectricity, a piezoelectric ring energy harvester is designed and tested in this study, such that the harvester can be used to power electric devices in the closed-circuit condition. Output energies across the external resistive load are evaluated when the ring energy harvester is subjected to harmonic excitations, and various design parameters are discussed to maximize the power output. In order to validate the theoretical energy harvesting results, laboratory experiments are conducted. Comparing experiment results with theoretical ones, the errors between them are under 10% for the output voltage. Laboratory experiments demonstrate that the ring energy harvester is workable in practical applications.


2015 ◽  
Vol 25 (12) ◽  
pp. 1550171 ◽  
Author(s):  
Mattia Coccolo ◽  
Grzegorz Litak ◽  
Jesús M. Seoane ◽  
Miguel A. F. Sanjuán

In this paper, we study the vibrational resonance (VR) phenomenon as a useful mechanism for energy harvesting purposes. A system, driven by a low frequency and a high frequency forcing, can give birth to the vibrational resonance phenomenon, when the two forcing amplitudes resonate and a maximum in amplitude is reached. We apply this idea to a bistable oscillator that can convert environmental kinetic energy into electrical energy, that is, an energy harvester. Normally, the VR phenomenon is studied in terms of the forcing amplitudes or of the frequencies, that are not always easy to adjust and change. Here, we study the VR generated by tuning another parameter that is possible to manipulate when the forcing values depend on the environmental conditions. We have investigated the dependence of the maximum response due to the VR for small and large variations in the forcing amplitudes and frequencies. Besides, we have plotted color coded figures in the space of the two forcing amplitudes, in which it is possible to appreciate different patterns in the electrical power generated by the system. These patterns provide useful information on the forcing amplitudes in order to produce the optimal electrical power.


Author(s):  
Edwar Romero ◽  
Michael R. Neuman ◽  
Robert O. Warrington

Energy harvesting from environmental sources such as motion, light, and temperature changes, has been demonstrated with commercially viable products (such as human-powered flashlights, solar-powered calculators, and thermal-powered wristwatches). Vibration or motion is an attractive environmental energy source due to its abundance and availability. A new electromagnetic energy harvester presented here is found to be capable for scavenging energy from human motion. The electrical power output of an inertial energy scavenger is proportional to the acceleration-squared-to-frequency (ASTF) and the quality (Q) factor. Human motion is associated with large ASTF values and low Q factors while machine vibrations are usually related with the opposite. Thus, passive energy harvesting from human activities could generate as much power as the one available from machine harvesters. The limit for such inertial generator is estimated to be on the order of 1mW/cm3. This paper reviews the energy harvesting limits, the energy generation from human activities, and the development of a new oscillating electromagnetic generator. This energy harvester is built with a permanent magnet (PM) ring with multiple poles and a gear-shaped planar coil. The PM ring has attached an eccentric proof mass for converting external movement into oscillations or rotations, these oscillations induce an electrical potential on the planar coil. As much as 3.45μW of power have been generated with a prototype at a frequency of 2.7Hz on a laboratory shaker and 2.35μW had been obtained when positioned laterally on the hip while walking.


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