Battery-less Sensing Networks for Food Quality Control with Power Efficient Wireless Power Transfer System and Communication Capabilities

联合国粮食及农业组织估计，每年约有13亿吨粮食被浪费，约占全球生产的供人类消费的粮食的30%。易腐食品过早腐烂的主要来源是在收获、包装、运输和储存过程中。有害微生物会感染食品，通常在食品包装的运输和储存过程中携带。一个有效的关键粮食参数监测系统可以及时发现需要，如运输条件的调整以及粮食分配计划的调整。可用的智能传感器可以检测食品的新鲜度、成熟度、微生物病原体的浓度和排放的气体。其中许多传感器无毒，可用于非侵入性食品监测。其中一些传感器提供颜色变化等视觉信息，而另一些传感器提供小的传感电流或电压，可以有效地监控并以无线方式传输到中央办公室，以便采取适当的行动。然而，这些智能传感器面临的主要挑战是，它们需要电池才能实现远程操作。该项目旨在开发一种无电池的绿色监测系统，该系统带有传感节点，可以包括在每个食品容器中。食品容器监控系统测量关键的食品参数，如PH值、温度和湿度。拟议的绿色技术具有成本效益、可重复使用且不需要电池。这项提议的研究目标是开发一种无线联网传感系统，该系统具有无电池传感节点，将监测和报告关键的食品参数。食品包装将配备一个可以无线接收能量的半导体芯片，为传感和通信功能提供动力。采用无线功率发射器和网络控制单元的中央单元将被安装在关键位置，为感测节点供电。无线接收的能量存储在超级电容器中，可以多次重复使用。这项研究将研究使用相位优化算法的功率传输技术，以加快无线功率传输过程。相位校准算法将把功率束聚焦在最远的传感节点的方向上。当充满电时，在11分钟的无线供电过程中积累的能量应该能够使传感节点传输系统至少运行100毫秒。由于无线供电天线传输覆盖的所有传感节点都可以同时供电，因此控制单元可以同时供电并与多个传感节点通信。每个食品容器都与一个识别码相关联，该识别码允许在其运输、储存和分发阶段进行无线跟踪。在这个项目中，将考虑100个食品容器和一个覆盖20米长的典型运输容器的网络原型，以展示拟议的无电池无线传感网络系统在现实世界应用中的可扩展性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The Food and Agriculture Organization of the United Nations estimated that approximately 1.3 billion tons of food are wasted every year, which represents about 30% of all food produced globally for human consumption. The major sources of premature decomposition in perishable food arise during the harvesting, packaging, transportation, and storage processes. Harmful microorganisms infect the food and are usually picked up during the transportation and storage of the food packages. An efficient monitoring system of critical food parameters can detect timely needs such as adjustment of transportation conditions as well as adjustment of food distribution plans. Available smart sensors can detect food freshness, ripeness, concentration of microbial pathogens, and emitted gases. Many of these sensors are not toxic and can be used for non-invasive food monitoring. Some of these sensors provide visual information such as color changes while some others provide small sensing current or voltages that can be efficiently monitored and wirelessly transmitted to the central office for proper actions. However, the main challenge of these smart sensors is that they require batteries to achieve long-range operation. This project aims to develop a battery-less green monitoring system with sensing nodes that can be included in every food container. The food container monitoring system measures critical food parameters such as PH, temperature, and humidity. The proposed green technology is cost effective, re-usable and does not require batteries. The research objective of this proposal is to develop a wireless networked sensing system with battery-less sensing nodes that will monitor and report critical food parameters. The food package will be equipped with a semiconductor chip that can receive energy wirelessly to power the sensing and communication functions. A central unit employing a wireless power transmitter and a network control unit will be installed in a key location to power the sensing nodes. The wirelessly received energy is stored in supercapacitors that can be reused multiple times. The research will study power beaming techniques using a phase optimization algorithm to speed up the wireless power transferring process. A phase calibration algorithm will focus the power beam in the direction of the farthest sensing node. When fully charged, the energy accumulated during 11-minute wireless powering should enable the sensing node transmission system to operate for at least 100 milliseconds. Since all sensing nodes covered by the wireless powering antenna's transmission can be simultaneously powered, the control unit can simultaneously power and communicate with multiple sensing nodes. Every food container is associated with an identification code that allows wireless tracking during its transportation, storage, and distribution stages. In this project, 100 food containers and a network prototype covering a typical 20-meter-long transportation container will be considered to demonstrate the proposed battery-less wireless sensing network system’s scalability in real-world applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.