MIT CSAIL scientists have developed a new user interface that allows them to integrate common tags with object geometry in order to make them 3D printable as ‘InfraredTags’.
The brain behind these new tags is 4th-year MIT CSAIL PhD student Mustafa Doga Dogan.
According to Dogan, unlike standard barcodes affixed to products which may be removed or detached or become otherwise unreadable over time, InfraredTags are unobtrusive as they are invisible, and far more durable, given that they’re embedded within the interior of objects fabricated on standard 3D printers.
In order to find a suitable variety of plastic that IR light can pass through, Dogan turned to a small German company that manufactures customized plastic filaments. These were then tested using a spectrophotometer at an MIT lab.
What Dogan discovered was the plastic remained opaque to visible light but turned transparent or translucent to IR light.
The next step for the team was to experiment with techniques for making tags on a printer.
One option was to produce the code by carving out tiny air gaps – proxies for zeroes and ones – in a layer of plastic.
Another option, assuming an available printer could handle it, would be to use two kinds of plastic, one that transmits IR light and the other – upon which the code is inscribed – that is opaque.
The dual material approach seems more preferable as it provides a clearer contrast and thus be more easily read with an IR camera.
The novel tags themselves could consist of familiar barcodes, which present information in a linear, 1D format, notes Dogan.
What’s more, 2D options – such as square QR codes and so-called ArUco (fiducial) markers – could further pack more information into the same area.
The MIT CSAIL team has also developed a software ‘user interface’ that specifies exactly what the tag should look like and where it should appear within a particular object.
Multiple tags can thus be placed throughout the same object, in fact, making it easy to access information in the event that views from certain angles are obstructed.
Dogan and his collaborators have so far created mugs with bar codes engraved inside the container walls and beneath a 1-millimeter plastic shell, which can be read by IR cameras.
They’ve also fabricated a Wi-Fi router prototype with invisible tags that reveal the network name or password, depending on the perspective it’s viewed from.
Image and content: MIT CSAIL