Recent Techniques for Harvesting Energy from the Human Body

The human body contains a near-infinite supply of energy in chemical, thermal, and mechanical forms. However, the majority of implantable and wearable devices are still operated by batteries, whose insufficient capacity and large size limit their lifespan and increase the risk of hazardous material leakage. Such energy can be used to exceed the battery power limits of implantable and wearable devices. Moreover, novel materials and fabrication methods can be used to create various medical therapies and life-enhancing technologies. This review paper focuses on energy-harvesting technologies used in medical and health applications, primarily power collectors from the human body. Current approaches to energy harvesting from the bodies of living subjects for self-powered electronics are summarized. Using the human body as an energy source encompasses numerous topics: thermoelectric generators, power harvesting by kinetic energy, cardiovascular energy harvesting, and blood pressure. The review considers various perspectives on future research, which can provide a new forum for advancing new technologies for the diagnosis, treatment, and prevention of diseases by integrating different energy harvesters with advanced electronics.     

Neisseria Meningitidis Detection Based on a Microcalorimetric Biosensor With a Split-Flow Microchannel

This paper proposes and demonstrates a novel microcalorimetric sensor for detecting Neisseria meningitidis. To eliminate additional heating structures and calibration steps, a split-flow microchannel is integrated into the microcalorimeter. The split-flow microchannel constantly maintains the output of the microcalorimeter near a zero level without the use of any heating elements when there is no biochemical reaction. With the use of the split-flow microchannel, an active heating element such as a heater is no longer required. In addition, to improve the sensitivity of the microcalorimeter, a thermal sensing component, which is a thermopile in this case, has been fabricated on a high thermal resistivity layer, which reduces the parasitic heat transfer to the silicon substrate and concentrates the released thermal energy to the thermopile. The characteristics of the proposed microcalorimeter were investigated by measuring the reaction heat of the biotin-streptavidin pairs. The sensitivity of the microcalorimeter was measured to be 0.21 V/cal. Then, a biological reaction between Neisseria meningitidis group B (NMGB) and its antibody was detected by using the proposed microcalorimeter. In order to verify the reliability of the measurement, exactly the same number of NMGB was reacted with its antibody and an optical density was measured by an enzyme-linked immunosorbent assay as a known reference.     

基于传热理论的热电能量转换系统集成分析

热电能量转换系统可实现热能和电能的直接转换。在一个完整的热电系统中,热电器件与冷热端换热器组成热阻网络,该热阻网络与冷热源之间的换热对系统性能具有决定性影响。该文从网络节点间的耦合传热关系出发,分析了外部换热对系统内部温度分布的影响,得到了实际热环境中热电系统输出性能的近似理论表达式。在此基础上,该文建立了外部换热条件与系统峰值输出功率的直接关系,并提出一套热电能量转换系统设计策略,可用于热电发电系统的快速设计。     

Study of thermal stability of CoSb3 skutterudite by Knudsen effusion mass spectrometry

Thermoelectric materials play an important role in the field of renewable energy for their ability of thermal energy conversion into electricity (thermoelectric generator) and reversibly electric energy conversion into thermal energy (thermoelectric heat pump or Peltier cooling). Doped CoSb₃ based skutterudites represent one of the very promising categories for the development of highly efficient thermoelectric materials for the conversion of waste heat to electricity. The thermoelectric efficiency, however, is closely related to thermal and phase stability as the current materials contain volatile elements (Sb, Sr, Yb, etc.), which can evaporate at operation conditions and thus cause structure changes and damage the thermoelectric properties. For a better understanding of the thermal behaviour of complex multicomponent CoSb₃ based skutterudite systems, a study of the thermal stability of primary CoSb₃ skutterudite is necessary.In this work, the thermal and phase stability of primary CoSb₃ skutterudite prepared by ball milling and hot pressing was investigated using thermal analysis and Knudsen effusion mass spectrometry performed on a Netzsch STA 409 CD/3/403/5/G apparatus, a specially-adapted type of the commercial STA 409 CD - QMS 403/5 Skimmer Coupling Instrument. Results, including data on phase transformations and those from vapour pressure measurements of antimony, supported by measurements of diffusion profiles and microstructure observations are summarized and used for evaluation of the long term thermal stability of the material.     

基于风电消纳的热电系统储热模型仿真

为了有效解决电热联合系统弃风严重、煤耗量较高的问题,基于风电消纳的热电系统储热模型.融合不同的系统组建电热联合系统,以热电联产机组最小煤耗及最低成本为目标,通过风电消纳需求提升系统中用户需求的灵活性,同时挖掘用户的需求响应侧潜力,组建基于风电消纳的电热联合系统储热模型.采用粒子群算法对电热联合系统储热模型进行求解,得到...     

利用环境余热供电的无线温度测量系统设计

无线测量节点的供电是无线测量系统在实际应用中受限制的主要问题之一.为解决此问题提出了一种收集工业生产现场环境余热并转换成电能为无线测量节点供电的方法.设计了由多个无线温度测量节点和一个Sink节点组成的无线温度测量系统.无线温度测量节点以CC2530为核心处理器,用热电偶测量温度,节点电源由能量收集模块供给.能量收集模块用热电片收集环境余热,以LTC3109为核心构成电源管理模块从而获得3.3 V输出电压.设计了上位机软件实时显示和保存Sink节点收到的各测温节点的温度数据.实验表明,在一定环境条件下能量收集模块可以为无线温度测量节点提供工作电源,为无线测量节点供电提供了一种参考解决方案.     

从环境中获取能量的无线传感器节点

研制了一种可从环境中获取能量的无线传感器节点,该节点用太阳能光伏电池和温差电池作为生能器件,用超级电容器和锂离子电池作为储存器件,并采用低功耗的能量管理策略,实现了能量的充分利用。研究了在夏季和冬季时超级电容器和锂离子电池的充电特性,并给出了无线传感器节点的功率曲线。实验表明,在夏季,太阳能光伏电池和温差电池在四天内可将锂离子电池充满,充满后的锂离子电池可在无光照的情况下保证无线传感器节点连续工作七天。     

Energy harvesting projects

This article examines how harvesting environmental energy in sensor networks changes the way an application developer views energy management, and discusses prototype devices. Then it proposes devices that combine energy harvesting and data acquisition. Then it explores novel approaches for optimizing the power extracted using piezoelectric materials. The final one explores kinetic and thermal energy harvesting from human users' activities. We usually use energy harvesting systems to convert and collect the environment's energy flows. A new wearable computing concept is considering these energy flows to be data flows as well. Current piezoelectric energy harvesting research falls into two key areas: developing optimal energy harvesting structures and highly efficient electrical circuits to store the generated charge or present it to the load circuit. Our research focuses primarily on the first area, in which the goal is to create small, lightweight structures that couple very well to mechanical excitation and converts the most usable electrical energy.     

Level set-based topology optimization for the design of a peltier effect thermoelectric actuator

Thermoelectric actuators are a type of thermal actuator that generates motion through the input of thermal energy by thermoelectric devices. Thermoelectric actuators utilize thermal expansion and contraction effects, achieved by heating and cooling appropriate parts of the mechanism, which enables specified motions to be carried out and can provide quicker response times than those of typical thermal compliant mechanisms that rely on thermal expansion effects alone. However, the need to consider both thermal expansion and contraction effects makes the design process more complex. This paper proposes a topology optimization method, especially appropriate for the conceptual design of thermoelectric actuators, that uses a level set function to represent structural shape profiles so that optimized configurations have clear structural boundaries. Several numerical examples of thermoelectric actuator design problems are presented to confirm the effectiveness and utility of the proposed method.     

碳纳米管薄膜气流热电发电机性能测试分析

基于碳纳米管薄膜的热电特性,设计了一种新型的薄膜式气流热电发电机。当热气流在碳纳米管薄膜材料表面流动时,在薄膜平面内形成温度梯度,通过塞贝克效应将热能直接转换为电能。利用浮动催化化学气相沉积法制备了导电性较好的透明碳纳米管薄膜,建立了气流热电发电机实验模型,对其输出电压进行了测试。实验表明:与传统的固定热源热电发电机相比,该气流热电发电机的输出电压较高。提出了集流体动力、流固耦合换热、热电效应于一体的多物理场耦合发电机制,对该实验结果进行了解释。碳纳米管薄膜气流热电发电机容易集成加工,可解决微光机电系统的电源问题,具有广阔的应用前景和实用价值。     

一种新型MEMS微波功率传感器的理论模型与优化设计

提出了一种新型的MEMS微波功率传感器.与传统的结构相比,新结构具有测量误差小、设计简单、使用方便等显著优点.然后在全面考虑了热传导、热对流、热辐射三种传热机制的基础上,对传感器的主要部分即热电堆建立了热模型,进而导出了灵敏度、时间常数、噪声的理论解析式.最后根据拉格朗日乘数法原理,以给定的时间常数和噪声大小为约束条件,求得灵敏度达最大时热偶长度和串联数目的最佳值.     

Wearable master device for spinal injured persons as a control device for motorized wheelchairs

This paper describes a wearable, master device for people with a spinal injury who can move their neck and shoulders but cannot move their legs and arms. A device that measures the movements of their neck or shoulder can help them to drive a wheelchair. The sensors of such a wearable master device must be lightweight, small, and easily attached to cloth. Therefore, optical fiber curvature sensors are used to measure the human body motion. For a previously developed wearable master device, two calibration and mapping methods with, the sensors are proposed to extract 2-DOF human shoulder motions. One is constructed with simple geometric equations. The other is constructed with a multilayered artificial neural network. The two methods are compared. Experimental results show that the wearable master device can be used effectively for a 2-DOF input device for handicapped persons. It was also shown that a subject can control a mobile robot with the wearable master device.     

Design and deployment challenges in immersive and wearable technologies

The current century has brought an unimaginable growth in information and communications technology (ICT) and needs of enormous computing. The advancements in computer hardware and software particularly helped fuel the requirements of human beings, and revolutionized the smart products as an outcome. The advent of wearable devices from their development till successful materialisation has only taken less than a quarter of a century. The huge benefits of these smart wearable technologies cannot be fully enjoyed until and unless the reliability of a complete system is ensured. The reliability can be increased by the consistent advancements in hardware and software in parallel. User expectations actually are the challenges that keep the advancements alive while improving at an unmatchable pace. The future of wearable and other smart devices depends on whether they can provide a timely solution that is reliable, richer in resources, smaller in size, and cheaper in price. This paper addresses the threats and opportunities in the development and the acceptance of immersive and wearable technologies. The hardware and software challenges for the purpose of development are discussed to demonstrate the bottlenecks of the current technologies and the limitations that impose those bottlenecks. For the purpose of adoption, social and commercial challenges related to innovation and acceptability are discussed. The paper proposes guidelines that are expected to be applicable in several considerable applications of wearable technologies, for example, social networks, healthcare, and banking.     

Development of a wrist-worn calorie monitoring system using bluetooth

Methods and tools for monitoring real-time human body information in daily life are required for advanced healthcare. In this study, a method for estimating energy expenditure during health exercises was evaluated and a wrist-worn sensing system based on the method was developed. Pulse monitoring was used to calculate energy expenditure by estimating oxygen uptake from a correlation between heart rate and oxygen uptake. Bluetooth technology was utilized for sending data by wireless communication. By the newly developed system, energy expenditure during exercise can be estimated considering individual difference and distinguishing changes in grade or load. Our goal is to construct a miniaturized wearable system that monitors vital signs and has many applications for healthcare. The study suggests that a wearable pulse sensing system proposed could provide useful information for healthcare.     

Nanowire silicon as a material for thermoelectric energy conversion

In order to use silicon as an efficient thermoelectric (TE) material for TE energy conversion, it is necessary to reduce its relatively high thermal conductivity, while maintaining the high power factor. This can be done by structuring silicon into 1-D structures or nanowires (NWs). Due to nanostructuring phonon scattering with the surface of such wires is drastically increased. This can result in a reduction of the thermal conductivity at a factor of 100 with respect to bulk silicon. Fabrication of vertical silicon NWs using ICP-cryogenic dry etching (Inductive Coupled Plasma) is described as a concept for CMOS-compatible integration of NW arrays instead of single NWs into a TE converter device. The uniform height of the NWs allows to connect simultaneously all NWs of an array. The realized NWs have diameters down to 180?nm and their height was selected between 1 and 10?μ. Measurement of electrical and thermal resistance of single silicon NWs with different diameters will be presented which was done in a scanning electron microscope (SEM) equipped with nanomanipulators. Furthermore, measurements will be shown of the thermal conductivity and the Seebeck coefficient of NW arrays.     

微机械热电堆红外探测器的设计

阐述了微机械热电堆的设计原理、所用材料及主要结构,并研究了3×3阵列的微机械制造工艺,该热电堆结构支撑结构为氮化硅—氧化硅—氮化硅的复合介质膜。热电偶材料采用多晶硅和铝,热电偶采用并列排布的结构,对冷端覆盖了绝热层,用以提高热电堆的探测率。由于该制作工艺与标准IC工艺兼容,使得硅基热电堆红外探测器得到了越来越广泛的应用。     

基于MEMS技术的双凸台微型热电能量采集器的仿真和制备

基于KOH腐蚀工艺设计并制作了具有双凸台结构的微型热电能量采集器,运用有限元法仿真器件在一定温差下的温度分布;并对器件建立了数学模型,分析凸台结构的几何参数等对器件输出性能的影响。仿真结果表明：随着顶部凸台高度的增加,温差的有效利用率逐渐升高;随着顶部凸台边长的增加,有效温差利用率逐渐降低;随着热冷端热阻的减小,器件的有效利用温差、开路电压、回路电流、输出功率都逐渐升高。从工艺上证明,基于MEMS技术的双凸台结构的微型热电能量采集器是可以加工和制备的。     

Novel soft bending actuator-based power augmentation hand exoskeleton controlled by human intention

This article presents the development of a soft material power augmentation wearable robot using novel bending soft artificial muscles. This soft exoskeleton was developed as a human hand power augmentation system for healthy or partially hand disabled individuals. The proposed prototype serves healthy manual workers by decreasing the muscular effort needed for grasping objects. Furthermore, it is a power augmentation wearable robot for partially hand disabled or post-stroke patients, supporting and augmenting the fingers’ grasping force with minimum muscular effort in most everyday activities. This wearable robot can fit any adult hand size without the need for any mechanical system changes or calibration. Novel bending soft actuators are developed to actuate this power augmentation device. The performance of these actuators has been experimentally assessed. A geometrical kinematic analysis and mathematical output force model have been developed for the novel actuators. The performance of this mathematical model has been proven experimentally with promising results. The control system of this exoskeleton is created by hybridization between cascaded position and force closed-loop intelligent controllers. The cascaded position controller is designed for the bending actuators to follow the fingers in their bending movements. The force controller is developed to control the grasping force augmentation. The operation of the control system with the exoskeleton has been experimentally validated. EMG signals were monitored during the experiments to determine that the proposed exoskeleton system decreased the muscular efforts of the wearer.     

Issues in the design and use of wearable computers

Wearable computers are fully functional, self-powered, self-contained computers that allow the user to access information anywhere and at any time. In this paper, design issues for wearable computers are discussed, including power considerations, use of input devices, image registration, and the use of wearable computers for the design of smart spaces. Application areas for wearable computers are presented, including medicine, manufacturing, maintenance, and as personal assistants. Finally, future research directions for wearable computers are indicated.     

BLE Mesh组网的可穿戴设备低功耗研究

针对目前可穿戴式设备功耗高的问题,本文进行了基于BLE Mesh组网的可穿戴设备低功耗的研究.以可穿戴单兵冲击波损伤测评系统为例,设计了一款基于Mesh组网的单兵冲击波损伤测评系统,该系统在原有系统的基础上增加了一个蓝牙组网.由于可穿戴设备采用纽扣电池供电,为了保证该系统的功耗不能有大幅度的增加,本文采用泛洪算法和低功...