Energy Harvesting Materials for Smart Fabrics and Interactive Textiles

智能织物和交互式纺织品（SFIT）被定义为能够感知来自环境的刺激并以预定方式对其做出反应或适应的纺织品。例如，智能纺织品/服装可以集成传感器/执行器、处理和通信，用于健康监测、消费品和汽车行业等应用。智能织物和交互式纺织品代表了下一代织物，开发它们的潜在机会是巨大的。在最近与纺织品社区的接触中，特别是与智能织物和智能服装的开发人员的交谈中，很明显，将电子功能集成到织物中的主要障碍是所需的便携式电源。例如，虽然导电轨道可以印在织物上，或导电纱线编织到织物中，但目前任何集成设备的电源都是标准电池。这需要常规连接，并且在洗涤过程中必须反复更换和拆卸。无论织物的功能如何集成，目前都无法替代使用分立电池为系统供电。能量收集（也称为能量清除）涉及将环境中存在的环境能量转化为电能。能量收集现在是一个重要的研究课题，诸如PowerMEMS， IEEE MEMS, Transducers， DTIP和Eurosensors等会议都至少有一个关于这个主题的会议。能量采集器没有电池的能量密度（给定体积的能量存储），但提供集成电源的吸引力，将持续整个应用寿命，不需要充电或更换。该项目将专注于从两种来源收集能量：动能和热能，所有这些都被认为是为移动电子设备供电的有前途的方法。-动能收集-例如，从人体运动中可以获得大量的动能。人体运动，以大振幅、低频率的运动为特征，同时也能施加大的力。据估计，每一步可获得67W的能量。-热能收集-利用塞贝克效应将热梯度转换为电能，可以从热源（如人体）收集能量。人们一直对利用体热发电为可穿戴设备供电感兴趣。例如，精工生产了一款以人体热量为动力的腕表。据报道，在温度差为5k的情况下，从700 mm^2的器件中获得的功率密度为0.14微米/毫米^2，这通常可用于可穿戴应用。该提案涉及使用快速印刷工艺和活性印刷油墨来实现能量收集织物。这将导致低成本，易于设计，灵活和快速的方式来实现能量收集纺织品/服装。喷墨和丝网印刷都是纺织工业中广泛使用的图案沉积工艺。所提出的丝网和喷墨印刷工艺具有许多优点，包括低成本、可重复性、灵活性、适合中小型系列和批量生产、开发时间短、与各种纺织品兼容以及沉积各种材料的能力。将研究油墨和相关的印刷参数，以实现正在处理的应用中能量收集膜的定制设计和布局。这项研究将提供一个适用于各种不同织物的材料和工艺工具箱，使用户能够开发出最适合他们要求的能量收集织物。

Smart fabrics and interactive textiles (SFIT) are defined as textiles that are able to sense stimuli from the environment and react or adapt to them in a predetermined way. For example, smart textiles/garments can incorporate sensors/actuators, processing and communications for use in applications such as health monitoring, consumer products and in the automotive sector. Smart fabrics and interactive textiles represent the next generation of fabrics and the potential opportunities for exploiting them are enormous. During recent involvement with the textiles community and talking in particular to developers of smart fabrics and intelligent clothing, it has become clear that a major obstacle towards integrating electronic functionality into fabrics is the portable power supply required. For example, whilst conductive tracks can be printed onto, or conductive yarns woven into, a fabric, the power supply for any integrated device is presently a standard battery. This requires conventional connection and must be repeatedly replaced and removed during washing. No matter how integrated the functionality of the fabric becomes, at present there is no alternative to powering the system using discrete batteries. Energy harvesting (also known as energy scavenging) is concerned with the conversion of ambient energy present in the environment into electricity. Energy Harvesting is now a significant research topic with conferences such as PowerMEMS, IEEE MEMS, Transducers, DTIP and Eurosensors featuring at least one session on the subject. Energy harvesters do not have the energy density (energy stored for a given volume) of a battery but offer the attraction of an integrated power supply that will last the lifetime of the application and will not require recharging or replacement. This project will focus on harvesting energy from two sources: kinetic and thermal energy all of which have been identified as promising approaches for powering mobile electronics. - Kinetic Energy Harvesting - For example, there is a large amount of kinetic energy available from human motion. Human motion characterised by large amplitude, low frequency movements that can also exert large forces. It has been estimated that 67W of energy are available in each step . - Thermal Energy Harvesting - Harvesting of energy from heat sources (such as the human body) can be achieved by the conversion of thermal gradients to electrical energy using the Seebeck effect. There has been interest in the generation of power from body heat as a means to power wearable devices. For example Seiko have produced a wrist watch powered by body heat. Reported results for power densities achieved from micro-fabricated devices are 0.14 microW/mm^2 from a 700 mm^2 device for a temperature difference of 5 K, which is typically achievable for wearable applications. The proposal involves using rapid printing processes and active printed inks to achieve energy harvesting fabrics. This will result in a low cost, easy to design, flexible and rapid way to realise energy harvesting textiles/garments. Both inkjet and screen printed are fully accepted processes widely used in the textile industry for depositing patterns. The proposed screen and inkjet printing processes have many benefits including low-cost, repeatability, flexibility, suitability for small/medium series and mass production, short development time, compatibility with a wide range of textiles and the capability of depositing a wide range of materials. The inks and associated printing parameters will be researched to enable the bespoke design and layout of the energy harvesting films in the application being addressed. The research will provide a toolbox of materials and processes suitable for a range of different fabrics that enable a user to develop the energy harvesting fabric best suited to their requirements.