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DVD Laser Scanner Microscope
- striking 6y agoHugged to death. Archive link: https://archive.is/bpvKq https://archive.is/bpvKq
- StavrosK 6y agoWell this is amazing. Wow.
- roger_ 6y agoBring on the Chinese clones!
- GrumpyNl 6y agoGreat job, very impressive.
- neolog 6y agoIt says the DVD bumps are 320-740 nm. Why does the demo image have only 1100 nm resolution?
- veonik 6y agoThe bumps are 740nm apart, but the laser is 1.1micrometer wide or 1100nm as shown in this diagram https://www.gaudi.ch/GaudiLabs/wp-content/uploads/Pits-1024x529.png https://www.gaudi.ch/GaudiLabs/wp-content/uploads/Pits-1024x...
- 1996 6y agoGiven the price of commercial confocal microscopes (even second hand), it could be very handy. I wonder if it would be possible to use different wavelengths (DVD and blueray lasers) to superpose images: even if the resolutions are different, it would allow using 2 reagents at once
- wombatpm 6y agoLet’s add micro fluidics and we can build a flow cytometer too!
- nomel 6y agoVery nice! I was going to do something like this for contactless transfer (ideally live) for a box of old cylinder records that I have. I still have the DVD head and fiber optics, for the confocal setup. Cylinder records are nice because they only have one channel of audio, with the waveform represented as a vertical displacement, perfect for something like this, on a screw drive, that just has to read depth and correct some slight tracking error.
- aidenn0 6y agoI don't know about cylinder records, but for typical vinyl disc records, the biggest issue I've heard about with contactless transfer is that a needle will displace dust particles while (obviously) a laser will not.
- Someone 6y ago“a needle will displace dust particles while (obviously) a laser will not.” I don’t think this setup will displace dust particles, but that’s not completely obvious. https://en.wikipedia.org/wiki/Optical_tweezers https://en.wikipedia.org/wiki/Optical_tweezers: “The trapped particles are usually micron-sized, or smaller.” I think the smallest dust particles are small enough to be manipulated in an optical tweezer.
- icu 6y agoI'm astonished that this is a DIY project... remarkable work!
- phkahler 6y agoThe most advanced technology can be reduced in price by 5 orders of magnitude as long as its needed to amuse the general public. Look at the supercomputer in your hand or pocket.
- earthscienceman 6y agoOnly 5? The raspberry pi 4 has nearly the same computational power as the servers I did my first research projects on and uses something like 1/100th of the wattage? I actually how no idea how much it cost but I imagine it was more than $5*50
- abstractbeliefs 6y ago5 orders of magnitude means the number of zeros. $50 -> $5,000,000
- bythreads 6y agowell, a lot of the cost of medTech equipment lies in the certification and SLA. there's a reason why a medical rated scissor is 1000 USD and the same sold on amazon is 20 USD.
- ChrisMarshallNY 6y agoThat is an awesome job. Confocal systems are six- to seven-digit bits of kit.
- beowulfey 6y agoWhat a fantastic piece of work! I just built the open theremin project from the same group. I love the open hardware movement. As someone who does confocal microscopy all the time this is particularly awesome.
- Arrath 6y agoThat is super cool!
- rkagerer 6y agoThis project was aided by earlier efforts hacking the Blu-ray laser from the XBox to turn it into a PCB printer. The original work is also really interesting http://www.diyouware.com/node/161 http://www.diyouware.com/node/161
- noisy_boy 6y agoTangential question: does anyone have recommendation for a good beginner's microscope? Preferably that plays well with Linux and can be used to record photos/short videos etc. Something to get the kids excited :)
- buescher 6y agoTake your chances with any of the inexpensive USB microscopes. I remember being thrilled as an adult to pick up one of the old Intel QX3 microscopes for photographing small parts. Anything you get in that vein will be much better today.
- avian 6y ago~50 EUR, random no-name USB microscopes are surprisingly good these days. I use them for inspecting PCBs and SMT solder jobs. Model names seem to change daily, but they are all very similar. Standard USB video device-class, so no software necessary. I just use guvcview under Linux. Pick one that has "full HD" in the name - it's usually not true 1080p, but in my experience the picture quality is still better than the other ones that will have a PAL-like sensor in it. Also, get one with a stand where you can adjust the height of the scope above the object with a screw.
- steve_adams_86 6y agoI got one used from a university for around $50. I can mount my phone onto it (aftermarket attachment) to get pretty cool images. I don’t have any handy now, but here are some I took with my phone just in my hand. https://imgshare.io/image/ppVR4g https://imgshare.io/image/ppVR4g https://imgshare.io/image/ppVlc7 https://imgshare.io/image/ppVlc7 https://imgshare.io/image/ppVaiq https://imgshare.io/image/ppVaiq My kids really enjoy it, so that’s good enough for me. I’d definitely take a look around for cheap used stuff!
- noisy_boy 6y agoThanks! The photos are quite impressive - I was thinking of buying a new one but having seen these, I'll probably also look for a good quality used one.
- rafaelturk 6y agoThis is AMAZING, what a fantastic project!
- martyvis 6y agoIt seems almost meta that they have scanned the pips on a CD https://www.gaudi.ch/GaudiLabs/wp-content/uploads/LaserScanCD.png https://www.gaudi.ch/GaudiLabs/wp-content/uploads/LaserScanC...
- iforgotpassword 6y agoOnly tangentially related, but are there any projects out there that modify CD or DVD readers to make it possible to read the raw (analog) pits and lands from the disc? When I was rescuing the last batch of burned CDs from my teen years a few years ago I unsurprisingly had some with lots of read errors. Googling around only lead me to forum threads where people recommended certain drives that would be very good at error recovery, but I thought it might be even better if you could get the raw stream from the disc and then do all the EFM reversal etc in software with more advanced analysis, brute forcing etc. But nothing of this kind seemed to exist.
- londons_explore 6y agoA major issue is that tracking (ie. Getting the laser to follow the route of the written data) is usually the thing that fails when reading disks. Even if you had access to raw laser data, you can't fix the tracking after reading it...
- agumonkey 6y agoside note, the magnetic adjustment coils on laser lenses are a thing of beauty..
- flotzam 6y agoOn https://web.archive.org/web/20090318021921/http://club.cdfreaks.com/f52/offsets-handling-syncing-audio-data-vs-q-channel-111913/#post726955 https://web.archive.org/web/20090318021921/http://club.cdfre... someone writes: 'I used an oscilloscope to find a sweet spot in the analog signal path of an audio CD player (an old Sanyo - the older the better, for this kind of stuff...) where a pre-filtered and amplified version of the laser readout is available - in this particular player, this is basically a test header marked "EFM" (which provides a good hint to its function - it's the last analog stage of the signal, just prior to entering the digital Fourteen-to-Eight demodulator). This point is probed and fed into a high-speed AD converter (12 bit res, 50 Msamples/sec) that is hooked to an FPGA. I implemented a flank detector and a run-length encoder in VHDL.' And later in the thread: 'Old audio CD players are so amazingly stupid, they will happily "play" CD-ROM discs if you feed it with one. This is truly ideal for analysis purposes.'
- Waterluvian 6y agoI was expecting the pits of a CD to be of two clear sizes. But I see a lot of range. Is error correction something that's in constant operation for all discs of all qualities and ages?