scholarly journals Investigating energy harvesting technology to wirelessly change batteries of mobile devices

2018 ◽  
Author(s):  
◽  
Neetu Ramsaroop

Mobile devices have recently become powerful computing tools for aiding daily tasks. However, their batteries discharge quickly, even if they are not being used mainly because of the heavy computation tasks required by the multimedia applications that run on them. The swift turnover time on the battery life span is challenging as frequent charging is required to keep the device functioning. This is a major bottleneck because of the current energy optimisation crisis, user inconvenience due to constant charging of a battery and erratic nature of the electricity supply in some areas. In the current research project, the primary aim was to explore the energy harvesting technology innovation of radio frequency to wirelessly recharge the batteries of mobile devices. This implied an alternative way of charging the batteries of mobile devices without the need for a physical charger to connect to an electrical outlet. Energy harvesting, which involves making use of free energy from the atmosphere is the most innovative energy efficient wireless charging technology because mobile devices are constantly transmitting radio signals. Radio signals are initially received from the atmosphere through an antenna. Thereafter, these signals are converted using a rectifier circuit, from alternating current into direct current which is then utilised to recharge the battery of a mobile device. This research study adopted a mathematical modelling and simulation research methods. The model involved building an RF energy harvesting prototype. This prototype model displayed the limitations to be considered. The LTSpice simulation software was used to test the feasibility of combining diodes, capacitors and antenna type based on the limitations of the prototype model. The result of this research project demonstrates the building of a radio frequency harvesting circuit that can store a minimum load of 5mV that is required to charge the battery of a mobile device. Moreover, it has explained an alternative storage of the acquired energy using a supercapacitor compared to a mobile device battery.

Author(s):  
Robin Deegan

Humans are approaching a new and intriguing time with regards to Mobile Human Computer Interaction. For years we have observed the processing power, memory capabilities and battery life of the mobile device increase exponentially. While at the same time mobile devices were converging with additional technologies such as increased connectivity, external peripherals, GPS and location based services etc. But what are the cognitive costs associated with these advancements? The software used on mobile devices is also becoming more sophisticated, demanding more from our limited mental resources. Furthermore, this complex software is being used in distracting environments such as in cars, busses, trains and noisy communal areas. These environments, themselves, have steadily become increasingly more complex and cognitively demanding. Increasingly complex software, installed on increasingly complex mobile devices, being used in increasing complex environments is presenting Mobile HCI with serious challenges. This paper presents a brief overview of five experiments before presenting a final experiment in detail. These experiments attempt to understand the relationship between cognition, distraction, usability and performance. The research determines that some distractions affect usability and not performance while others affect performance but not usability. This paper concludes with a reinforced argument for the development of a cognitive load aware system.


Author(s):  
Anastasia V. Daraseliya ◽  
Eduard S. Sopin

The offloading of computing tasks to the fog computing system is a promising approach to reduce the response time of resource-greedy real-time mobile applications. Besides the decreasing of the response time, the offloading mechanisms may reduce the energy consumption of mobile devices. In the paper, we focused on the analysis of the energy consumption of mobile devices that use fog computing infrastructure to increase the overall system performance and to improve the battery life. We consider a three-layer computing architecture, which consists of the mobile device itself, a fog node, and a remote cloud. The tasks are processed locally or offloaded according to the threshold-based offloading criterion. We have formulated an optimization problem that minimizes the energy consumption under the constraints on the average response time and the probability that the response time is lower than a certain threshold. We also provide the numerical solution to the optimization problem and discuss the numerical results.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Syed Luqman Shah ◽  
Irshad Ahmed Abbasi ◽  
Alwalid Bashier Gism Elseed ◽  
Sikandar Ali ◽  
Zahid Anwar ◽  
...  

Cloud computing has emerged as an attractive platform for individuals and businesses to augment their basic processing capabilities. Mobile devices with access to Internet are also turning towards clouds for resource-intensive tasks by working out a trade-off between resources required for performing computation on-device against those required for off-loading task to the cloud. However, as with desktop clients, mobile clients face significant concerns related to confidentiality and integrity of data and applications moved to and from the cloud. Cloud-related security solutions proposed for desktop clients could not be readily ported to mobile clients owing to the obvious limitation in their processing capabilities and restrained battery life. We address this problem by proposing architecture for secure exchange and trusted execution between mobile devices and cloud hosts. We establish a symmetric-key-based secure communication channel between mobile and cloud, backed by a trusted coordinator. We also employee a Trusted Platform Module- (TPM-) based attestation of the cloud nodes on which the data and applications of mobile device will be hosted. This gives a comprehensive solution for end-to-end secure and trusted interaction of the mobile device with cloud hosts.


Author(s):  
Mingyi Liu ◽  
Wei-Che Tai ◽  
Lei Zuo

Portable, wearable, and mobile devices are becoming more and more popular in the past two decades. Those devices rely on batteries heavily as power source. However, the limited life span of batteries constitutes a limitation. Human body energy harvesting has the potential to power those devices, thus replacing batteries or extending battery life. Harvesting positive muscle work from human body can be a burden, and exhausts the wearer. In this paper, we developed a biomechanical energy-harvesting device that generates electricity by harvesting negative work during human walking. The energy harvester mounts on the ankle and selectively engages to generate power between the middle stance phase and terminal stance phase, during which the calf muscles do negative work. The device harvests negative energy by assisting muscles in performing negative work. Test subjects walking with the device produced an average of 0.94 watts of electric power. From treadmill test, the device was shown to harvest energy only during the negative work phase, as a result it has the potential to not to increase the metabolic cost. Producing substantial electricity without burden on the wearer makes this harvester well suited for powering wearable, portable, and mobile devices.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4034
Author(s):  
Arie Haenel ◽  
Yoram Haddad ◽  
Maryline Laurent ◽  
Zonghua Zhang

The Internet of Things world is in need of practical solutions for its security. Existing security mechanisms for IoT are mostly not implemented due to complexity, budget, and energy-saving issues. This is especially true for IoT devices that are battery powered, and they should be cost effective to be deployed extensively in the field. In this work, we propose a new cross-layer approach combining existing authentication protocols and existing Physical Layer Radio Frequency Fingerprinting technologies to provide hybrid authentication mechanisms that are practically proved efficient in the field. Even though several Radio Frequency Fingerprinting methods have been proposed so far, as a support for multi-factor authentication or even on their own, practical solutions are still a challenge. The accuracy results achieved with even the best systems using expensive equipment are still not sufficient on real-life systems. Our approach proposes a hybrid protocol that can save energy and computation time on the IoT devices side, proportionally to the accuracy of the Radio Frequency Fingerprinting used, which has a measurable benefit while keeping an acceptable security level. We implemented a full system operating in real time and achieved an accuracy of 99.8% for the additional cost of energy, leading to a decrease of only ~20% in battery life.


2016 ◽  
Vol 11 (6) ◽  
pp. 32 ◽  
Author(s):  
Shwu-Ing Wu ◽  
Rou Jyun Chen

<p class="ArticleTitle">In recent years, the increasingly innovative and diverse mobile devices have significantly promoted the mobile device-based shopping. What factors influence this kind of shopping? Will consumers purchase things with mobile devices? These are two topics that need to be explored. Through the literature analysis and the empirical research, this study aims to analyze the quality of information, system, service and mobile devices on the mobile device-based shopping platform. Moreover, it studies the attitude of consumers towards mobile device-based shopping, their willingness to adopt the shopping method and the behavioral relationship model in the actual mobile device-based shopping as well as compares the groups of different frequencies of the Internet use in terms of the relationship model.</p>  With the convenient sampling, this study made an investigation among some of those who had experienced shopping on such mobile devices as tablets or smart phones. The 765 retrieved valid copies of questionnaire were divided into three groups—“often”, “average” and “seldom” according to the frequency consumers undertook mobile device-based shopping and were then compared. The results showed that there were significant differences among the three groups in four relationship paths, including: 1) the information quality of the mobile device-based shopping platform has more significant positive influence on consumers’ attitude path of mobile device-based shopping in the “average” group than in the other two; 2) the service quality of the mobile device-based shopping platform has more significant positive influence on consumers’ attitude path of mobile device-based shopping in the “seldom” group than in the other two; 3) the preference for mobile device-based shopping has much significant positive influence on the behavior path of mobile device-based shopping in the “often” group. According to the research results, different groups have different behavior models. These results can serve as reference information in the decision-making of those who establish mobile device-based shopping platforms and manufacture mobile devices.


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