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

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.