Recently I have read many papers on animal research, and I found that one of the most difficult problems is how to solve the problem of charging sensors. After all, for many small animals, the battery size of the sensor is limited, and many studies are not convenient to recycle the sensor for charging (such as animal research living in radiation areas).
So I wonder if wireless charging technology can be used to charge such sensors. I have read many studies in this area and found that it is technically feasible, but I have spent a long time searching on the Internet and have not found any application of wireless charging technology on animal sensors. Existing wireless charging companies do not have sensor-related services. I want to know why there are no similar applications? Is it because of money or lack of technical support? I am also curious about how big the current wireless charging receiving device is. And whether it can be installed on small animals. Even if it is large now, how to make it smaller in the future?
Even though it is big now, it is still useful in long-term research such as animals in the Chernobyl radiation zone. After all, wireless charging devices can be used to charge drones or robots without recycling sensors. I think If there is such a device, it may solve many problems. Thank you for your reply!
17 October 2024 11:05am
Hi Yu.
The wireless charging devices I've used in the past only work over a very short range on the order of millimeters. They are all mainly Qi type chargers using inductive coils. They also need to be precisely centered for maximum power transfer. Because of those limitations, I've quickly given up on using them for device charging and just stick with cables. Not sure about other wireless charging methods.
Akiba
17 October 2024 3:03pm
In addition to the practical problem already mentioned - how do you get the animal to cooperate and place the sensor on a charging pad for extended, regular durations - there's also the health concerns - wireless power transmission, like any form of RF, can have health impacts [primarily] due to tissue heating (or ionisation, although I don't think that's a concern with the relatively low wavelengths used in standards like Qi, in the 100 - 200 kHz range).
The physiological impact of RF absorption on humans isn't as well-studied as you might assume (and mainly around certain "popular" wavelengths, like those used in cellular radios). I expect it's dramatically less-well-studied in non-human animals.
18 October 2024 9:42am
I've studied this in depth for a data-logger I was working on. What I've found was that even though the IC's you've listed are very small, the coil needed to actually feed the charging components need to be rather sizeable to charge the battery at a decent enough rate.
If you've got a small logger which also has a wireless antenna, the coil itself also de-tunes the antenna which can result in worse performance of the logger overall.
For bigger sensors on bigger animals, I do think harvesting RF-radiation would be feasible if you'd be able to make it really low power (eg. very low sampling rates and very power efficient components).
18 October 2024 12:45pm
I believe that it has been used with caged animals in the lab. For wild animals its range is impractically short.
Akiba
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