It should be possible to sandblast your own fiducials. I know a headstone maker who uses a rubber cutting machine to make stencils which he uses when he sandblasts text or images onto stone. The rubber is roughly 10mm thick and has a sticky back. After you have cut the fiducial just remove the protective layer from the areas that you want to stick to the plastic. Removing the white areas would work best.

After the piece is sandblasted you just need to glue another piece onto it to bring it up to the height of your laser.

Another possible way would be to make your own mould http://www.instructables.com/id/Urethane-Rubber-Molds/ and use a clear epoxy resin in a 2 step process. First fill the mould half way let it set and sandblast the fiducial pattern on. Then place the piece back in the mould and pour some more resin on top of the the fiducial pattern to bring it up to the height of the laser. I have never worked with epoxy resin so this needs testing.

You could also make fiducials for ftir just look how deep sandblasting gets into stone

http://www.sandblastedstonesigns.com/

Uhm, about the spbogie post

What about taking a cheap digital wristwatch, iluminating it’s LCD with IR leds instead the standard yellow leds it have to watch the time at night, and “reprogramming” it’s “software” to show customizable fiducials?

I give the wristwatch example, but what I mean is that this kind of electronics are kinda cheap and is not so difficult to design an easily reproducible schematic of a prototype, running with a very simple PIC microcontroller, very compact, able to switch between various fiducials, and powered with a watch battery.

I will do some research on that.

I think there is an easier solution for self illuminated fiducials.
There are companies in China that manufacture and sell EL Badges. They are the approximate size of a standard fiducial marker. They usually come with some dumb design, but they could easily be made as full light plate with no design on them. The fiducial could then be applied as a vinyl decal (you can get it cut cheap at a sign shops)
These badges run on watch batteries and have an on/off button.

The tricky part is that the minimum for manufacturing may be 10,000, but I could find out more if people are interested in it.

Alex

tangibleinteraction.com

“tangible is the new digital”

I have a feeling that the easiest thing to do would create a block with an embedded button on one side that turned on IR leds inside the cube.  And the sides of the block would have designs cut into them, similar to a pumpkin carving.  Also a external, embedded visible LED would be obviously needed in order to know when the cube was on.
See quick mock up sketch attached

Alex,
The problem with the EL(electro-luminescent) Badges is finding such a badge in the InfraRed spectrum. This is why I specifically went with an LED powered nightlight. If you were to go the EL route you would have to work directly with the manufacturer to get them made in the IR spectrum. The end goal is something similar to that badge, but LEDs seem the far more practical route.

PeauProductions,
That is definitally a possibility. The main difficulty lying in getting the IR diffused evenly. I’m also trying to come up with a way to have them turn on when placed on the table, but not on other surfaces. School has started back up now though, so MT research/concept testing time is limited.

haha, yeah I feel you on the lack of time since school started (I start next week).

To diffuse the light, we could probably use tracing paper or similar material, the same way LCD setups use it to evenly diffuse a non-standard backlight.  I have 100 or so IR LEDs ordered on ebay last week coming soon, so once my table is up, ill see if the box idea works.

Paper might work, but all you really need is hot glue:

http://www.instructables.com/id/Hot_Glue_LED_Diffusion/

Seems to me it would make better diffusion than paper alone.

I know I’m reviving a really old thread, but I’m just wandering if there have been any advancements in fiducials with the LLP method? I’m thinking of building a table using LLP and although its not necessary, fiducials are definitely something I would love to play with.