4DBioprinter I am new here so don't know to answer in your thread Bostjan64. I think I want a lamp (but not 100% sure). My surface will go from a 400x400 microm2 to 4x4 mm2. I am not interested in a focal point, but in a surface really (getting all the surface with the same intensity). Basically I am 3D printing hydrogels and I want to photocrosslink them. Ideally a apparatus premade because my lab doesn't have the equipment to assemble electronics...I am a biologist. But if it was easy enough I am willing to go through youtube videos!

How thick are the films you are using? The 405 nm laser is cheap enough, and with simple optics, you can cover 16 mm2. A 1W 405 nm battery-powered laser from China can be purchased for a couple hundred euros. The green laser would cost maybe 100 times more and would not likely be able to run on battery power, because the diodes are much newer and rarer, but it's also doable. Are you pressing the gels between glass plates to do this? I'm not familiar with the process. What kind of budget do you have in mind?

The 3D printing fabrication is layer by layer. So if I crosslink everylayer, the thickness would be 400-600 microm. If I do the crosslinking after all layers are printed, the size would be around 4 mm thick (4x4x4 mm3 cube basically). The hydrogel is completely exposed, so no, not pressing between glass (which I presume it will help for the light source to reach the sample). If I knew it worked, budget would be between €1000-1500, but since I am doing trial error for now, I would rather go to a cheaper option

thank you very much btw for your answer and the follow up

Oh, I don't think you'll be able to get both UV and Green light to that energy density for only 1500 Euros. If you want to try something cheap, you could get an old Bluray player out of the electronic waste and cannibalize the optic sled from it. If you can harvest a good 12VDC power supply for it, then you might be able to get the 405 nm assembly made completely from repurposed electronics and optics for nothing. If you want a modulated pulse, you can make an interrupter circuit for the power supply for probably about 10 Euros. If you get really lucky, you might be able to find an old projector with a powerful RGB source, and then you can cannibalize the green light from the source and incorporate that as well, but most commercial green lights aren't nearly as bright, in terms of measured intensity, because the human eye is much more sensitive to green light. A green direct diode LASER, as I mentioned, with any sort of considerable power, will probably cost well over a thousand euros on its own. I've done some low budget stuff through LASER-BTB in the past with 405 nm 1 W focusable battery-operated lasers, for material processing, and it was really cheap to buy direct from the factory. The optics were far from perfect, but I was able to get everything working for under 250 euros. The power output ended up being a little higher than advertised, which worked well for my application, but you might want to be careful, especially if you order through a Chinese distributor, since they often misrepresent their product's power. Best of luck!

thanks Bostjan64