Zhaoshu Yang

针对在轨中长期驻留阶段航天员衣物洗涤的迫切需求, 以及地面传统洗衣技术无法适用于微重力环境的问题, 设计了一种基于雾化臭氧原理的空间洗衣平台. 该平台利用超声雾化阵列将液态水雾化浸润衣物, 通过紫外照射产生臭氧用于除菌; 采用有限元方法对微重力环境下液滴与衣物的附着情况、洗衣平台的内流场进行了仿真分析, 重点分析了在微重力和地面重力条件下液滴在洗衣腔体内分布的均匀性区别. 在此基础上, 根据相对湿度、臭氧浓度等指标确定了预雾化时间、内循环风扇流量等参数; 随后, 采用等效系统质量的方法对雾化臭氧洗衣平台的上行资源代价进行了评估, 该洗衣技术在轨运行一年的资源代价仅为商选洗衣技术的15.7%, 当在轨运行5年后, 相比于完全将衣物作为消耗品上行, 可节省61.9%的等效系统质量. 通过分析两种方法的收益平衡时间点可知, 对于任务周期超过5个月的空间站任务、周期超过2.5个月的深空探测任务, 发展在轨洗衣技术更具资源代价优势. 本文的工作有望为未来中国在轨洗衣技术的发展提供参考.

One of the crucial issues for applying electret/triboelectric power generators in the Internet of Things (IoT) is to take full advantage of specific high voltage signals and enable self-powered sensing. Therefore, inspired by Miura-origami, we present an innovative origami power generator (OPG) constructed from only one piece of electret thin film. The Miura-origami architecture realizes a generator with excellent deformability and stretchability and makes it unnecessary for any auxiliary support structure during the compress-release cycle. Various parameters of the generator are intensively investigated, including the excitation accelerations, excitation displacements, numbers of power generation units and deformation degree of the device. When stimulated with 5.0 g acceleration at 15 Hz frequency, the generator with 8 generation units can obtain an instantaneous peak-to-peak voltage and a remarkable optimum peak power of 328 V and 2152 μW at 50 MΩ, respectively. In addition, the regulable shape and multiple generation modes of the device greatly improve its applicability in various vibration energy collection requirements. Based on the above results, a hexagonal electret generator integrated with six-phase OPGs is developed as a “Buoy on Sky,” after which the signal waveforms generated from internal power generators are recognized with 92% accuracy through a neural network algorithm that identifies the vibration conditions of transmission lines. This work demonstrates that a fusion of origami art and energy conversion techniques can achieve a multifunctional generator design satisfying the requirements for IoT applications.

The development of wearable electronics and sensors is constrained by the limited capacity of their batteries. Therefore, energy harvesting from human motion is explored to provide a promising embedded sustainable power supply for wearable devices. Herein, the principles, development, and applications of human motion excited energy harvesters are reviewed. The energy harvesters are classified based on the human motions with distinguished characteristics: center of mass motion (COM), joint motion, foot strike, and limb swing motion. According to the motion characteristics, the principles, features, and limitations of different energy harvesters are discussed, and the power generation performances are compared. Finally, various self‐powered applications enabled by embedded energy harvesters are introduced, so as to show the great potential of embedded energy harvesting systems in boosting the development of the wearables.