ben dot krasnow at gmail
Hey Ben,I've got a question regarding photo-resistive film, since you've been using it a lot in your projects from what i recall.The basic question is how thick is a layer of such film, and what is the maximum thickness you can get from a single layer?Now to expand a little upon the question:I was wondering if its possible to reproduce a fingerprint from a fingerprint scan without the use of a high quality 3D printer.The plan was to use a somewhat high quality laser or maybe inkjet printer to print the image of the scanned fingerprint, and then expose a layer of photoresistive film to it, develop it, etch it and apply a new layer on top of it and repeat the process.The idea would be to get a sort of mold of the fingerprint while the needed accuracy is about 0.075-0.1mm detail, problem is i don't really know how photoresistive film behaves. (an alternative would possibly be to apply new layers of copper with a pre-applied film on it and just do it in a controlled temperature environment).After having a mold producing a copy of the fingerprint using silicon or gelatin isn't hard.The overall idea of the project is to demonstrate a security hole in the upcoming implementation of a biometric database by the government where i live, where basically a cheap and easy to make copy of anyone's fingerprint can be produced at home.
Hi! I am not sure if my youtube comment actually got posted or not so i am also asking here. I want to do the freeze-drying as an experiment in school and i would like to ask some questions about how your experiment went. Is that okay with you? Thanks in advance!
Alex, in the semiconductor industry "thin" photoresist is usually 1 micron thick, or less, eg 800nm. "Thick" photoresist is maybe 3-4 micron thick. The thickness is controlled by the photoresist's viscosity and spin-coat speed. You can apply multiple layers to build up thickness, theoretically without bound. Check this out: http://istouchidhackedyet.com/
Railon, please ask your question publicly (G+, blog, youtube), so that everyone can benefit from the conversation.
Is it possible to buy 1..10 grams of liquid crystal? Minimum order on Alibaba is 1 kg or more.
This vendors sells smaller bottles: http://www.alibaba.com/product-gs/1458702385/Nematic_liquid_cristal.html I have not purchased small quantities of LC on Alibaba, so I couldn't say for sure how this will work.
Do you think it would be possible to make switchable privacy glass like http://smarttint.com/ does? I would like some but I don't want to spend a whole $80 for one square foot.