Hi Gourav,
Can we have a chat? 
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Hi All
@WayneWayneHello has a Kickstarter running for “LadyBug: A New Way to Scan Macro - Take huge and stunning panoramas of the microscopic world, even in three dimensions.” see here (via @Take):
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Dear Prof. Edwin En-Te Hwu and Gaudi, I have tried to contact professor asking about the publication (https://pubs.acs.org/doi/pdf/10.1021/acssensors.8b00340) via university email in Denmark.
I have found this thread after endeavoring of days.
I am interested in writing a fully understandable documentation for average readers on how to build a OPU-based microscope that does not require external materials but which also does not contain too much theoretical excessiveness. While I was missing so many details in your supplementary material such as code and PCB artwork (https://drive.google.com/drive/folders/1G-EXtJZ3PajhJJ8Ppi6O5qTkXGD7UWDV), Gaudi’s work in his website seems to be a candidate that I can actually start with. I find that many of Gaudi’s projects are more than interesting. Thanks.
I am doing my PhD in computer science in Germany, dealing with mathematical optimisation for image understanding. Yet, my bachelor’s programs were about Electronics engineering and Material engineering back in Korea, which would allow me to well-pursuit the projects being discussed here. I am glad to find this thread. Even though working on OPU-based microscope is limited to be a weekend project, I am very serious.
Hi @fordicus Happy to hear you like our work and that you want to work on open documentation. In fact I am follow different DIY Atomic force microscopy (AFM) projects for a while and as far as I understand there is still no real open source project that is properly documented. @Edwin did a great job a while ago developing a DIY ready AFM, based on a Optical Pickup Unit (OPU). Some of it is documented on this popular instructables page:
However as I understand the full plans were never released. I guess also because Edwin was using some software (and maybe electronics and datasheets) that he got from the industry and that he could not release openly.
I also met people from the LegoToNano project. Students that tried to build a AFM based on Lego as an exchange project with China (Shenzhen) I guess. Guess they were also inspired by Edwins work but developed a different kind of mechanical stage because they were afraid to get in trouble with some intellectual property. They had a kind of functioning electronics and were working on software. Have not heard from the project for a while and maybe they stopped:
https://www.london-nano.com/news-events/ucl-and-chinese-students-join-forces-build-low-cost-nanoscope
Then there was the startup company stromlinet-nano that used to sell the Strømlingo AFM kit. A well developed kit that was also based on Edwins work (maybe a spin-off). However this kit was never open source and only commercially available. Now I can not find the company anymore. Maybe they went out of business?
http://www.stromlinet-nano.com/
Then I developed the DVD laser microscope. This is basically an optical laser scanning microscope, not an AFM. It works ok and is open source. We also got an almost complete reverse engineering of the OPU now. I think it could be developed further into an AFM by adding a piezzo stage and a AFM lever. That would be awesome and the closest we can get to an open source AFM at the moment I guess.
http://www.gaudi.ch/GaudiLabs/?page_id=652
This is all just my understanding. Please anyone, @Edwin correct if you know more.
And @fordicus please share your thoughts if you are interested on working on this.
Best,
Urs
Just found this on the wayback machine on stromlinet-nano - there is some open source code at the bottom of the page too:
https://web.archive.org/web/20190123214215/http://www.stromlinet-nano.com/
And some videos here:
https://www.youtube.com/channel/UCp088Kl_0aCI0Xdmiil2w7Q
Due to NDA, the OPU datasheet is not possible to release. But I shared 3 OPU driver designs. I also replied your email.
Hi Gaudi,
You are right, my institute licensed the AFM technique to that company but they also have NDA. So I am not allowed to post their circuit design. However the other OPU driver designs were in my review article. Hope that helps. :)
Cheers,
Edwin
As I know they are selling many Arduino controlled AFMs to many countries haha…
oh…I didn’t know…I haven’t contact them for a while…
Thanks for the fruitful information.
At the moment, I want to focus on the baseline of the OPU-based microscope as I do not have many experiences.
And if possible, I am interested in acquiring colored-information by filtering or by modulating devices with their working frequencies,
which means that I still stick to the optical information, at the moment.
I have successfully contacted Prof. Edwin En-Te Hwu with many details.
Unfortunately, I only can work on this project during weekends as I am a fully-funded Ph.D. student.
But let us keep in touch. I am very serious with this project
“http://www.stromlinet-nano.com/” revived today due to my contact via Facebook channel. But the quoted price through my email was 3K US dollars at minimum. It seems the price did not change for years and is higher than my target price. My goal is to build and reveal a budget design such that a high school student can easily build one; I regard this project similar to Linux NPO. A high school student is not necessarily able to pay 3K USD. I am a fully grown PhD student who is interested in computer vision level research application using OPU-based microscope, but am reluctant to pay 3K USD. I respect the efforts of stromlinet and of many other companies. But I want to push the price further while keeping a level of quality such that the study platform can be shared by as many people as possible.
The first goal is to have a colored imaging system. PHR-803T has three laser wavelength: UV 405nm (HD-DVD), Red 650nm (DVD) and IR 780nm (CD) …[http://www.diyouware.com/node/161]. I wanted to surrogate one of them with a green laser. But once I started reading the paper by Prof. Hwu again, all the optical path is fine-tuned for in-built wavelength from the source of light. It means that it is difficult to just replace one of them to achieve a green color pick up. Thus, I have sat back from this idea at the moment. Please let me know if you have some idea on how to achieve color image with Xbox360’s OPU where we are missing green color reading. Thanks.
Continuing the work on this from last 3 months amidst lockdown. As Prof. @Edwin already know about the software-based quantitative analysis using CD/DVD players without any modification.
We found that these softwares like Opti drive control, kprobe etc require specific manufacturers of Optical drives like plextor,liteon etc.
Although another group used a software called Isobuster but it still requires further processing to effectively perform quantitative analysis.
Refer: https://www.sciencedirect.com/science/article/abs/pii/S0925400510004533
So we decided to make a software on our own. As of now we have the coding part done and are working on the GUI. The results are fully accessible unlike the softwares mentioned before and provide much higher control and we present the data in form of a CSV file or PDF etc depending on the choice. A sample result is given below.
readom.pdf (7.8 KB)
Apart from this, we are simultaneously working on getting the RF signal acquisition. Till now it has proven difficult because of the lack of documentation of the PCB of the DVD drives. So, @Edwin @gaudi if possible can you help me out with this because right now I don’t have access to labs because of the lockdown. Hope we can discuss this.
Hey,
this sounds great! I am also eager to play around with OPU for laser microscopy, AFM, laser actuators and more but bio-assays on disc sounds very interesting too - perhaps even more so with potential for custom discs with microfluidic systems and direct RF-reading. Planning to do some experiments with OPU as soon as I get to my lab in Berlin but currently stuck in Stockholm…
For RF I would suggest looking at all the software radio boards out there and GnuRadio as a software framework for working with them. I guess depending on the frequency range and bandwidth required cost of boards vary a lot from DVB-T sticks for 10 EUR that goes up to ca 1.6GHz with about 1 MHz bandwidth:
https://www.rtl-sdr.com/tutorial-creating-fm-receiver-gnuradio-rtl-sdr/
to e.g. LimeSDR up to 3.8 GHz and 61 MHz bandwidth and Ettus Research USRP systems like B200 that goes up to 6GHz with 56 MHz bandwidth. (I guess bandwidth is what is relevant).
Datasheets for OPU seems hard to come by unfortunately, for Sanyo SF-HD65/HD860 you can find some in mixed english and japanese here:
https://www.physik.uni-muenchen.de/lehre/vorlesungen/wise_17_18/science_with_electronics/references/
I guess it would be most useful to have a datasheet for PHR803T which seems to have become the standard for DIY-stuff but at least I haven’t found any datasheet out there - there is already a lot of knowledge however in all the projects that used it for different purposes, e.g. the diyouware link above.
I have a box of about 100(never counted them…) complete Samsung TS-P632 DVD+R/RW mechanisms with a chinese KMX Tech KWS-290F OPU that also seems fairly easily accessible but never found any datasheet for those either - also no blue laser there…
Cheers,
Bengt
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@bengtsjolen, what do you mean by direct RF-reading? Are you talking about resonance detection in surface features or milling the top off a chip and picking up signals?
Nobody has mentioned where the probes would come from. Would the idea be to buy or to DIY? I have no idea of the expense or difficulty respectively.
Dear all, it seems precision around 1µm is cheaply achievable with optical microscope.
As such resolution was my target, I decided to try with optical microscope alternatively.
But I am having difficult time finding ‘a proper xy stage’ for this purpose
(1µm precision observing microbiomes in shallow liquid)
because I want to ‘track’ the specimen with a software that I plan to write on my own.
A linear ‘xy stage’ seems they are often very expensive or just I am not experienced.
Could anyone give me some advice about where to find or simply build one?
The microscope that I am buying can be found in
@bengtsjolen , your RF reading idea is very interesting.
The Blu-ray OPU has >100MHz working bandwidth. The scanning bottleneck might be the VCM which has c.a. 1mm working distance but decrease 3db at second resonance…
On a spinning disk I guess bandwidth effectively translates to resolution and is then related to revolutions per time so quite scalable unless certain “centrifugal” force is required to drive e.g. a microfluidic system embedded in a disc. For AFM and other applications I guess it would have other implications - scanning rate / frame rate for AFM e.g…
Some more details on those SDR chips or agile transceivers:
USRP B210 uses Analog Devices AD9361 which has 4-channels of 12-bit ADC at 112 MHz sample rate.
LimeSDR has LM7002M which has 4-channels of 12-bit ADC at 120 MHz sample rate. The latter claims to be software configurable up to 120 MHz RF bandwidth which should correspond to 240 MHz sample rate though.
Historically SDR systems have been built with much more discrete parts such as VCO, mixers, ADC/DAC, filters etc but these 2 chips are highly integrated with basically everything on-chip which also gives them extreme flexibility such as RX/TX frequency ranges from 100 kHz to 6GHz or so.
Some of these kinds of ICs can receive a raw DC signal but I think both of these cannot so any DC signal probably need to be mixed with a carrier - the chip can generate the carrier though.
Also if looking at a signal that can effectively be seen as amplitude modulated (AFM tapping mode?) then the receiver part of those agile RF transceiver could be useful as well (also they have DACs at similar resolution and sample rates).