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，占全球生产供人类消费的所有粮食的30%左右。易腐食品过早分解的主要原因是在收获、包装、运输和储存过程中。有害微生物会感染食品，并且通常在食品包装的运输和储存过程中被携带。一个有效的关键粮食参数监测系统可以及时发现需要，如调整运输条件以及调整粮食分配计划。可用的智能传感器可以检测食物的新鲜度，成熟度，微生物病原体的浓度和排放的气体。这些传感器中有许多是无毒的，可用于非侵入性食品监测。这些传感器中的一些提供视觉信息，例如颜色变化，而另一些提供小的感测电流或电压，这些电流或电压可以被有效地监测并无线传输到中央办公室以进行适当的操作。然而，这些智能传感器的主要挑战是它们需要电池来实现远程操作。该项目旨在开发一种无电池绿色监测系统，其传感节点可以包含在每个食品容器中。食品容器监测系统可测量PH值、温度和湿度等关键食品参数。拟议的绿色技术具有成本效益，可重复使用，不需要电池。该提案的研究目标是开发一种无线网络传感系统，该系统具有无电池传感节点，可以监测和报告关键的食品参数。食品包装将配备一个半导体芯片，可以无线接收能量，为传感和通信功能提供动力。采用无线电力发射器和网络控制单元的中央单元将安装在关键位置，为传感节点供电。无线接收的能量存储在超级电容器中，可以多次重复使用。本研究将研究使用相位最佳化演算法来加速无线电力传输过程的电力波束技术。相位校准算法将在最远感测节点的方向上聚焦功率波束。当充满电时，在11分钟的无线供电期间积累的能量应使传感节点传输系统能够运行至少100毫秒。由于无线供电天线的传输覆盖的所有感测节点可以同时供电，因此控制单元可以同时供电并与多个感测节点通信。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、存储和分发阶段进行无线跟踪。在这个项目中，100个食品容器和一个覆盖典型的20米长的运输容器的网络原型将被考虑，以证明拟议的无电池无线传感网络系统在现实世界中的应用的可扩展性。这个奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

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.