Image credit: MIT News
Researchers at MIT have developed solar powered RFID sensors that work in both indoor and outdoor lighting conditions.
Improving RFID Tag Technology
Radio-frequency identification (RFID) tags utilize radio waves in order to communicate stored information. Currently, there are two kinds of tags available, passive ones that are powered by nearby RFID readers through radio waves, and active ones that utilize a local power source, such as a battery. These two kinds of tags are already being adopted by various industries such as automotive, energy, hospitality, IT, retail in a myriad of applications.
The new developments coming out of MIT are pushing this technology forward. They have innovated a new system that would allow these tags to work for years before replacement is required, as well as having the benefit of functioning at greater distances. Researchers created photovoltaic-powered sensors, made from thin-film perovskite cells, that can be adhered to the RFID tags in order to power them using light, even low indoor light.
Key Advancements in Solar Power
What the team at MIT have innovated isn’t something that hasn’t been tried before. Previously researchers have designed small solar-powered devices, but these versions have utilized conventional solar technology, which has required the use of expensive, bulky, inflexible components. Meaning that the devices established have often been inappropriate for widespread use in real world applications.
A solution to the drawbacks of using conventional solar power has been found by the Massachusetts based team. They innovated customized solar cells that incorporate layers of perovskite material between an electrode, cathode, and electron-transport layer materials. Using this structure allowed researchers to control the “bandgap” of each cell, securing it to be optimal for performing efficiently in various light conditions.
Tests were ran to evaluate the performance of the cells, and the results showed that they could communicate data at distances that were five times greater than those at which conventional RFID tags can work. This long range functionally opens the door to the capability of using one reader to monitor data from numerous inputs at once.
The tests showed that just 45 minutes of light exposure was sufficient in order to provide 3 hours of charge. Under fluorescent indoor lighting the cells were reaching up to 21.4% efficiency. The results demonstrate the enhanced performance of the new solar powered tags over conventional ones.
Estimations predict that the sensors have the potential to function for many years without degrading. Making many more applications of the sensors a possibility, such as monitoring of energy use, or tracking products moving through supply chains.
Low Cost Means Easy Adoption
What’s more is that the cells rely on the use of perovskite cells, which are cheap to construct. The cells can be printed using roll-to-roll manufacturing techniques, making them suitable for large scale production. This, coupled with the already low-cost technology of RFID tags, presents a genuine opportunity to numerous industries to adopt this affordable technology in numerous applications.
Given the cheap and easy method of manufacturing these sensors, the innovation achieved by the MIT team is making it possible to imagine a future which relies on billions of connected sensors for a number of jobs. The work will allow enhanced RFID tags which rely on solar energy harvesters that can be used within various industries, it will also support the growth and development of the Internet of Things, which is predicted to become fundamental to all industries in the near future.