Ultraconformable Integrated Wireless Charging Micro-Supercapacitor Skin

Conformable and wire-less charging energy storage devices play important roles in enabling the fast development of wearable,non-contact soft electronics.However,current wire-less charging power sources are still restricted by limited flexural angles and fragile connection of components,resulting in the failure expression of performance and constraining their fur-ther applications in health monitoring wearables and moveable artificial limbs.Herein,we present an ultracompatible skin-like integrated wireless charging micro-supercapacitor,which building blocks(including electrolyte,electrode and substrate)are all evaporated by liquid precursor.Owing to the infiltration and permeation of the liquid,each part of the integrated device attached firmly with each other,forming a compact and all-in-one configuration.In addition,benefitting from the controllable volume of electrode solution precursor,the electrode thickness is easily regulated varying from 11.7 to 112.5μm.This prepared thin IWC-MSC skin can fit well with curving human body,and could be wireless charged to store electricity into high capacitive micro-supercapacitors(11.39 F cm-3)of the integrated device.We believe this work will shed light on the construction of skin-attachable electronics and irregular sensing microrobots.

Designing an Effective Method for Automatic Electric Vehicle Charging Stations in a Static Environment

This article outlines an Effective Method for Automatic Electric Vehicle Charging Stations in a Static Environment. It consists of investigated wireless transformer structures with various ferrite forms. WPT technology has rapidly advanced in the last few years. At kilowatt power levels, the transmission distance grows from a few millimeters to several hundred millimeters with a grid to load efficiency greater than 90%. The improvements have made the WPT more appealing for electric vehicle (EV) charging applications in both static and dynamic charging scenarios. Static and dynamic WEVCS, two of the main applications, are described, and current developments with features from research facilities, academic institutions, and businesses are noted. Additionally, forthcoming concepts based WEVCS are analyzed and examined, including “dynamic” wireless charging systems (WCS). A dynamic wireless power transfer (DWPT) system, which can supply electricity to moving EVs, is one of the feasible alternatives. The moving secondary coil is part of the dynamic WPT system, which also comprises of many fixed groundside (primary) coils. An equivalent circuit between the stationary system and the dynamic WPT system that results from the stationary system is demonstrated by theoretical investigations. The dynamic WPT system’s solenoid coils outperform circular coils in terms of flux distribution and misalignment. The WPT-related EV wireless charging technologies were examined in this study. WPT can assist EVs in overcoming their restrictions on cost, range, and charging time.

Finger-actuated wireless-charging wearable multifunctional sweatsensing system for levodopa and vitamin C

Efficient portable wearable sweat sensors allow the long-term monitoring of changes in the status of biomarkers in sweat,which can be useful in diagnosis,medication,and nutritional assessment.In this study,we designed and tested a wireless,battery-free,flexible,self-pumping sweat-sensing system that simultaneously tracks levodopa and vitamin C levels in human sweat and detects body temperature.The system includes a microfluidic chip with a self-driven pump and anti-reflux valve,a flexible wireless circuit board,and a purpose-designed smartphone app.The microfluidic chip is used for the efficient collection of sweat and the drainage of excess sweat.The dual electrochemical sensing electrodes in the chip are modified with functional materials and appropriate enzymatic reagents,achieving excellent selectivity and stability.The sensitivities of the levodopa sensor and the vitamin C sensor are 0.0073 and 0.0018μA·μM^(-1),respectively,and the detection correlation coefficients of both exceed 0.99.Both sensors have a wide linear detection range of 0–100 and 0–1000μM,respectively,and low detection limits of 0.28 and 17.9μM,respectively.The flexible wireless circuit board is equipped with the functions of wireless charging,electrical signal capture and processing,and wireless transmission.The data recorded from each sensor are displayed on a smartphone via a self-developed app.A series of experimental results confirmed the reliability of the sweat-sensing system in noninvasively monitoring important biomarkers in the human body and its potential utility in the comprehensive assessment of biological health.

Optimized speed control for electric vehicles on dynamic wireless charging lanes: An eco-driving approach

As the adoption of Electric Vehicles(EVs)intensifies,two primary challenges emerge:limited range due to battery constraints and extended charging times.The traditional charging stations,particularly those near highways,exacerbate these issues with necessary detours,inconsistent service levels,and unpredictable waiting durations.The emerging technology of dynamic wireless charging lanes(DWCLs)may alleviate range anxiety and eliminate long charging stops;however,the driving speed on DWCL significantly affects charging efficiency and effective charging time.Meanwhile,the existing research has addressed load balancing optimization on Dynamic Wireless Charging(DWC)systems to a limited extent.To address this critical issue,this study introduces an innovative eco-driving speed control strategy,providing a novel solution to the multi-objective optimization problem of speed control on DWCL.We utilize mathematical programming methods and incorporate the longitudinal dynamics of vehicles to provide an accurate physical model of EVs.Three objective functions are formulated to tackle the challenges at hand:reducing travel time,increasing charging efficiency,and achieving load balancing on DWCL,which corresponds to four control strategies.The results of numerical tests indicate that a comprehensive control strategy,which considers all objectives,achieves a minor sacrifice in travel time reduction while significantly improving energy efficiency and load balancing.Furthermore,by defining the energy demand and speed range through an upper operation limit,a relatively superior speed control strategy can be selected.This work contributes to the discourse on DWCL integration into modern transportation systems,enhancing the EV driving experience on major roads.

Design and Application of Automatic Test System of Soil Water Characteristic Curve

[Objective] In order to better meet the requirement of crops on a more and more accurate water content under various planting environment of modern agri-culture, an automatic test system of soil water characteristic curve was designed by combining the conceptions of soil moisture content and soil water potential. [Method] Electronic soil moisture tension meter was used to determine the real-time tension value of soil moisture in the tested container, and the electronic Weigh sensor was used to determine soil Weigh. Minusing method was used to calculate soil moisture content, based on which the soil water characteristic curve was plotted. [Result] Through the filed survey of 2 different kinds of soil in Jiangsu Province, the results were as fol ows： soil of different composition showed different trend in soil water characteristic curve that the soil water characteristic relation of the sandy soil in the old course of the Yel ow River in Xuzhou was Y=-0.000 2X3＋0.027 7X2-1.644 5X＋38.161, R2=0.991 9; while the soil water characteristic relation of the saline-alkali soil in Jinhai Farm of Dafeng was Y=-0.00 2X2-0.426X＋39.905, R2=0.991 3. [Con-clusion] The automatic test system of soil water characteristic curve soil water char-acteristics curve could reflect soil moisture content and soil water potential, as wel as reflect the effectiveness of soil water to plant growth, providing basis for the sci-entific irrigation.

Comparison of electromagnetic exposure to child and adult from electric vehicle wireless power transmission

It is important to verify the safety of electric vehicle(EV)wireless power transmission for child passengers by studying the electromagnetic exposure difference between the child passengers and the adult passengers.The dielectric parameters of the child passengers’body were calculated under the operating frequency of 85 kHz.Using the finite element simulation software COMSOL Multiphysics,a model was established for the child passengers and adult passengers when the EVs charged by the wireless charging coil.This paper analyzed the distribution of magnetic induction intensity and induced electric field intensity generated on the body and head when the child passengers and adult passengers sat in four different positions.Additionally,the difference between the brain electromagnetic exposure values of children and adults was analyzed and compared with the limits set.The results showed that the electromagnetic exposure was the largest when the passenger sat in the co-driver position.The electromagnetic exposure level of child was slightly higher than that of adult at the same position,and the magnetic induction intensity and induced electric field intensity of both were much smaller than the public electromagnetic exposure recommendation values.

Towards Japan＇s Future EV-Friendly Highway Concept with In-motion Road-Embedded Wireless Chargers

This paper proposes a demonstration of the infrastructure concept of electric vehicles-friendly highways. EVs （electric vehicles） are gaining momentum as a bright prospect to replace conventional fuel-dependent ICE （internal combustion engine） as demand of EVs increase year by year in every country. However, due to battery capacity limitation and charging stations availability, EVs are mainly used in urban areas for short-range commuters rather than long-range journeys. This has resulted in EV usage concentrated in town and business areas. It is clear that EV usage for long distance driving is still in minimal priority due to inadequate battery performances and charging infrastructures insufficiency. The proposed concept is to solve range anxiety issues by wirelessly charging in-motion vehicles, particularly at highways namely DCH （dynamic charging highway）.

Empowering highway network:Optimal deployment and strategy for dynamic wireless charging lanes

Amid escalating energy crises and environmental pressures,electric vehicles(EVs)have emerged as an effective measure to reduce reliance on fossil fuels,combat climate change,uphold sustainable energy and environmental development,and strive towards carbon peaking and neutrality goals.This study introduces a nonlinear integer programming model for the deployment of dynamic wireless charging lanes(DWCLs)and EV charging strategy joint optimization in highway networks.Taking into account established charging resources in highway service areas(HSAs),the nonlinear charging characteristics of EV batteries,and the traffic capacity constraints of DWCLs.The model identifies the deployment of charging facilities and the EV charging strategy as the decision-making variables and aims to minimize both the DWCL construction and user charging costs.By ensuring that EVs maintain an acceptable state of charge(SoC),the model combines highway EV charging demand and highway EV charging strategy to optimize the DWCL deployment,thus reducing the construction cost of wireless charging facilities and user charging expenses.The efficacy and universality of the model are demonstrated using the classical Nguyen-Dupius network as a numerical example and a real-world highway network in Guangdong Province,China.Finally,a sensitivity analysis is conducted to corroborate the stability of the model.The results show that the operating speed of EVs on DWCLs has the largest impact on total cost,while battery capacity has the smallest.This comprehensive study offers vital insights into the strategic deployment of DWCLs,promoting the sustainable and efficient use of EVs in highway networks.

Soft,stretchable,wireless intelligent three-lead electrocardiograph monitors with feedback functions for warning of potential heart attack

Cardiovascular diseases(CVDs)are fatal chronic diseases,where electrocardiography(ECG)monitoring could be a prominent solution for early diagnosis.In spite of available commercialized,multilead ECG devices,bulky formats,discontinuous monitoring,and no safety alarm system significantly limit their practical applications.Herein,we present a soft,and stretchable,three-lead ECG device allowing continuous monitoring and wireless transmission of ECG signals.A newly developed organohydrogel patch with a strong adhesive ability(~9.9 kPa)and higher conductivity(~6.5 kΩ)is applied for high-quality ECG signals collection.With a long operation duration(6.5 h)and wireless transmission distance(20.9 m),it could fulfill most of the daily applications.Machine learning algorithms and the graphical user interface are used for real-time ECG monitoring and cardiac abnormalities diagnosis.The vibratory flexible actuator,which is triggered by cardiac abnormalities that need immediate medical treatment,is also integrated as a warning system for the user.As a newly reported stretchable multi-lead ECG device for long-term ECG signal monitoring,there is a high potential for improving users'life quality with the high-risk population of CVDs.

Energy-Efficient Minimum Mobile Charger Coverage for Wireless Sensor Networks

Sustaining an operational wireless sensor network (WSN) is challenging due to the persistent need of the battery-powered sensors to be charged from time to time. The procedure of exploiting mobile chargers (MCs) that traverse to the fixed sensors of the network and wirelessly transfer energy in an efficient matter has been considered widely as a promising way to tackle this challenge. An optimization problem, called the mobile charger coverage problem, arises naturally to keep all of the sensors alive with an objective of determining both the minimum number of MCs required meeting the sensor recharge frequency and the schedule of these MCs. It is shown that this optimization problem becomes NP-hard in high-dimensional spaces. Moreover, the special case of the homogeneous recharge frequency of the sensors has already been proven to have a tractable algorithm if we consider whether the 1-dimensional space is a line or a ring. In this work, we seek to find a delicate border between the tractable and the intractable problem space. Specifically, we study the special case of heterogeneous sensors that take frequencies of 1's and 2's (lifetime of 1 and 0.5 time units) on a line, conjecture the special case's NP-hardness, propose a novel brute-force optimal algorithm, and present a linear-time greedy algorithm that gives a 1.5-approximation solution for the problem. Afterwards, we introduce the energy optimization problem of the MCs with the minimized number and solve it optimally. Comprehensive simulation is conducted to verify the efficiency of using our proposed algorithms that minimize the number of MCs.

Analysis and Comparison of Two Wireless Battery Charger Arrangements for Electric Vehicles

The paper deals with wireless battery chargers(WBCs)for plug-in electric vehicles(PEVs)and analyzes two arrangements for the receiver of a series-series resonant WBC.The first arrangement charges the PEV battery in a straightforward manner through a diode rectifier.The second arrangement charges the PEV battery through the cascade of a diode rectifier and a chopper whose input voltage is kept constant.Figures of merit of WBCs such as efficiency and sizing factor of both the power source and the transmitter/receiver coils are determined.Afterwards,they are discussed and compared with reference to the case study of WBC for an electric city car.A proposal to optimize the efficiency of the second arrangement by a suitable selection of the chopper input voltage is presented.Measurements on the efficiency of the two arrangements are included to support the theoretical results.

Parametic Model for Optimization of Battery Capacity and Power Transmitters of On-line Electric Vehicles in Closed/Open Environments

An on-line electric vehicle(OLEV)uses a wireless charging phenomenon,in which power transmitters are installed beneath the road and the OLEV’s battery is charged remotely.This paper deals with the optimization of two key economic and design parameters,i.e.,the size of the battery and the power transmitters allocation.A complete model configuration of the OLEV system,including the vehicle design and power transmitter,is implemented using MATLAB/Simulink.The battery’s state of charge(SOC)rises and drops according to the vehicle’s velocity and power collection and consumption.The mixed integer programming(MIP)model is used for cost calculation.Therefore,with the help of the SOC graph and MIP model,the battery size and the number of power transmitters,along with their placements,are optimized.The proposed model is applicable to both closed and open environments as it accepts both regulated and deregulated velocities.Two test cases are performed for this purpose.The first test case deals with regulated velocity for which we have applied the KAIST campus OLEV’s velocity along with its 13 kWh battery size and 4 power transmitters,and then applied the suggested solution with the same velocity and route i.e.,8 power transmitters with shorter lengths and reduced battery size(3.25 kWh;one-fourth of the first case).SOC is found within limits at the end of the route,saving$1600 and validating the proposed model in this paper.For the second test case,we use deregulated velocity and optimize both parameters,using the same approach.

"Charge while driving"for electric vehicles:road traffic modeling and energy assessment

The aim of this research study is to present a method for analyzing the performance of the wireless inductive charge-while-driving(CWD)electric vehicles,from both traffic and energy points of view.To accurately quantify the electric power required from an energy supplier for the proper management of the charging system,a traffic simulation model is implemented.This model is based on a mesoscopic approach,and it is applied to a freight distribution scenario.Lane changing and positioning are managed according to a cooperative system among vehicles and supported by advanced driver assistance systems(ADAS).From the energy point of view,the analyses indicate that the traffic may have the following effects on the energy of the system:in a low traffic level scenario,the maximum power that should be supplied for the entire road is simulated at approximately 9 MW;and in a high level traffic scenario with lower average speeds,the maximum power required by the vehicles in the charging lane increases by more than 50%.