Miniature RFID tag solution

[JBWolf]

Hello,
I am interested in a low cost solution to miniature rfid tags.
I will be molding my own parts from epoxy and need to put an rfid chip inside each one.
The molded parts will be 2" x 1" x .5", the rfid tag needs to fit comfortably inside without touching the edges.

I plan to use this with the propeller chip and an rfid reader... frequency is not important to me.
The RFID tags need to be able to accept one write minimum, and lots of reads.
The molded parts containing the rfid tags will be fed at a fast speed through the reader (3 feet per second)... read distance is about 1/2".
I have searched everywhere including through digikey and even spoken with a representative but could only find a suitable tag for about $2/ea.... acceptable cost is <$0.30/ea
The 20mm round tags offered by parallax are above acceptable cost.

I have found a possible solution on ebay and contacted him, still awaiting response. List price puts them at $0.28/ea and within acceptable cost range.
http://www.ebay.com/itm/Alien-9662-3-x-1-UHF-RFID-Adhesive-Tag-RFID-Label-500lbls-roll-/160733951594?pt=LH_DefaultDomain_0&hash=item256c7d766a
I am looking at product numbers: J42 & 9613

Unfortunately I just do not know as much as I would like about RFID.
I am wondering if someone might know a solution to my needs.
Maybe since the read distance is so small, I might be able to get away with using an RFID IC without an antenna since the antenna seems to be 90% of the tag size?
I am wondering how much the epoxy will affect the read distance since the tag will be completely embedded and have to go through up to .25" of solid epoxy... not sure if this will make any difference at, or if it may absorb a considerable percentage.

I sincerely appreciate any help.
J

[max72]

Check Parallax:
http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/rfid/List/0/SortField/4/ProductID/427/Default.aspx

or maybe the capsule..
http://www.sparkfun.com/products/9416

If a Parallax reader is too big check this one:
http://www.sparkfun.com/products/8628
It has embedded antenna, and works rather well

Obviously the smaller the antennas the shorter the range..

Massimo

[JBWolf]

The requirements are the size (<.5" x <2") and the cost per tag up to a quantity of 100.
Acceptable cost is <$0.30/ea... anything over $0.30 and it will exceed our budget.

2nd most important, is that each tag must be writable atleast one time (WORM).

Readers are currently not of concern as the base unit does not have size constraints, and the planned read distance is less than one inch.

This is obviously something that will not be found in the parallax or sparkfun web stores. I have spent days searching, even went through every available product with a rep at digikey and could find nothing... until I ran across the one ebay auction that actually meets all of our requirements. I'm sure there are other products out there that are just what I'm looking for, probably made in China... problem is finding them.
I'm planning to do an extensive search through Alibaba next.
I need to find another product incase the ebay tags do not work for our needs

[Leon]

Check Parallax:
http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/rfid/List/0/SortField/4/ProductID/427/Default.aspx

or maybe the capsule..
http://www.sparkfun.com/products/9416

If a Parallax reader is too big check this one:
http://www.sparkfun.com/products/8628
It has embedded antenna, and works rather well

Obviously the smaller the antennas the shorter the range..

Massimo

That's not necessarily the case. A properly designed and matched short antenna will be be more effective than a long random length one.

[Toby Seckshund]

I remember reading somewhere that somebody bought a batch of "cheap" RFID cards and thet turned out to be just pieces of plastic.

I have to use a plastic RFID module at work. It is about 1.5" long and 0.5" diameter (counting the loop for the springback cord). It's a PITA when you are carrying stuff with both hands and need to get through a door, I keep meaning to try and clone it with Micah's AVR85 project.

http://scanlime.org/category/projects/rfid/

[JBWolf]

The read distance actually needs to be as small as possible.
They will be fed in at a high rate of speed and in close proximity... I may have to shield the reader so it does not read any tag except the one directly underneath/ontop of it.

[JBWolf]

The sample order of tags have arrived!
Each one measures 1/2" x 1/3" and are paper thin, laminated in plastic.
Read/Write distance = <20cm

Here is their posted specs:
Model: Alien 9613


Certification: ISO18000-6C（EPC GEN2）
Operating Frequency Global: ISM 902~928MHz
Operation Mode: FHSS
Antenna material: Aluminum
Carrier Frequency: ultrahigh frequency (UHF)
Detection Distance: <20 cm
Die-cut dimensions:: 12 x 9 mm
Antenna dimensions: 50 x 18 mm
RFID chip: Alien Higgs-3
User Memory: 512 Bits
Reading & Writing: 100000 Times (>10years)
Operating Temperature: -13°F to 122°F [-25°C to +50°C]
Storage temperature:-20°C to +80°C (-4°F to +176°F)



I managed to get a good closeup pic showing the chip.
9157491575

[JBWolf]

Now I need a writer+reader for use with these tags... Looks like 915mhz is the only reader available in this range.
I plan to use them only with the Propeller chip both for reading and writing.
$50 is a bit over what I can afford at the moment for an RFID writer... anyone have a recommendation for a 915mhz reader writer for use with the propeller that I can afford?
Was hoping to find something in the $30 or less range.

Right now I'm in prototyping so I need a combo reader/writer unit.
Eventually I will be writing the RFID tag data from a dedicated unit and issuing products with embedded tags out to people with an RFID reader base unit.

[JBWolf]

Oh btw Toby... these guys sell tags with very sensitive antennas that can be read at incredible distances for RFID.
The auction link above is to that very type of tag: model #9662
Measures 3" x 1" x .01" with a max read distance of 20 feet.

I'm betting if you were to copy your data to one of these tags, you could atleast extend your read range by a foot or two depending on the reader setup.
They are very thin so I'm sure you could open your keyfob and throw one of these in there.
Contact them about samples, I found the seller very easy to work with.

[Toby Seckshund]

The ones here are 125KHz, I stuck a loop of wire onto a 'scope to prove it a while ago.

I wanted to get one into a cheap plastic wrist casing so that the wall sensors could be pinged without letting go of anything (or doing a dance on one foot, to use that knee and get a free hand)