0
\$\begingroup\$

I'm looking for some ideas on how to detect some kind of material/tag that can be electrically distinguished amongst organic material, wood and iron. Such material/tag should be possible to detect from approximately 20-30cm, but there is one catch - tag cannot be bigger than 4mm in diameter and 1.5mm in thickness. I tried using UHF RFID tags, but for such small dimensional restraints maximum read distance that I could achieve was only something around 5mm with RAIN RFID tags from Murata. I was thinking about using metal or magnetic tag with inductive sensors, but first problem I encountered is that I couldn't find ones with my desired detection distance and other problem is that detection area contains stainless steel wires which could cause false detection signal.

Can you suggest me what tag and reader system I could use in such conditions?

EDIT:

More details about my project: The issue that I briefly described to you is a part of my project to monitor behavior of bees in and around apiary. Namely to manage diseases spread around apiary between beehives and also to monitor flight range of specific breeds of bees. I need to detect presence of infested, marked bee in a beehive that is considered healthy and also to detect if bee released at some distance from apiary has managed to come back to its beehive. Experiment will be conducted amongst many beehives (80-100) with 1-2 day interval, so traditional marking as in case of queen bee - with marker or glued plastic cap would be dramatically time consuming as I would have to remove each frame at each beehive and visually inspect presence of marked bees. For that reason I'm planning to attach tags to bees' thorax and then detect it through reader/sensor (hence the tag's dimensional restraints of 4mm diameter and 1.5mm thickness). Ideally I would walk by inspected beehive and scan it from the outside, through beehives' walls (which are typically made from wood or styrofoam). However such approach can be challenging for any scanning technology, so it is acceptable to remove beehive's roof and scan frames from the top without removing them (hence my required 20-30cm reading range). Each frame consists beeswax, stainless steel wires and nails, wooden construction and, of course, bees :) As I mentioned in me previous post RFID tags would be perfect for such purpose as I could even have specific ID for each individual bees, but reading range is too low for such small tags. So that's the reason why I'm here, looking for some ideas how to solve my problem, I hope you could suggest me some kind of solution :)

\$\endgroup\$
7
  • 2
    \$\begingroup\$ Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. \$\endgroup\$
    – Community Bot
    Commented Jul 4 at 21:17
  • 2
    \$\begingroup\$ shopping requests are off topic here \$\endgroup\$
    – jsotola
    Commented Jul 4 at 21:32
  • \$\begingroup\$ Hello and welcome. Could you clarify what you're wanting to achieve a bit? What kind of organic material do you mean? I don't understand the RFID portion: are you sticking tags on three objects? Many objects? Can you hold the objects still? How long do you have to read them? \$\endgroup\$
    – jonathanjo
    Commented Jul 4 at 22:10
  • \$\begingroup\$ qrcode and telephoto lens / laser scanning? \$\endgroup\$
    – jonathanjo
    Commented Jul 4 at 22:41
  • \$\begingroup\$ your detection distance to tag size ratio is too high for any unfocussed field-based detection system like RF, magnetic, electrostatic. You need focussed means, optical for instance \$\endgroup\$
    – Neil_UK
    Commented Jul 5 at 4:29

1 Answer 1

Reset to default
0
\$\begingroup\$

I think the answer may be a system similar to that used in electronic catflaps which reads the code from a chip implanted in the animal. The chip is small enough to be attached to a bee, and the sensor is a coil which could be fitted around the hive entrance. The EM4095 datasheet should give you some ideas.

\$\endgroup\$
1
  • \$\begingroup\$ If you implement the entrance as a short pipe you can mount two readers in line to distinguish between leaving and coming bees. \$\endgroup\$
    – Jens
    Commented Jul 6 at 1:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.