Laser Sequencer uses Arduino to Enable Super-Microscope!

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[Philip]’s Laser control Arduino shield.

[Philip Nicovich] has been building laser sequencers over at the University of New South Wales. His platform is used to sequence laser excitation on his fluorescence microscopy systems. In [Philip]’s case, these systems are used for super-resolution microscopy, that is breaking the diffraction limit allowing the imaging of structures of only a few nanometers (1 millionth of a millimeter) in size.

Using an Arduino shield he designed in Eagle, [Philip] was able to build the system for less than half the cost of a commercial platform.

The control system is build around the simple Arduino shield shown to the right, which uses simple 74 series logic to send TTL control signals to the laser diodes used in his rig. The Arduino runs code which allows laser firing sequences to be programmed and executed.

[Philip] also provides scripts which show how the Arduino can be interfaced with the open source micro manager control software.

NicoLase1500EnclosureRender

As well as the schematics [Philip] has provided STEP files and drawings for the enclosure and mounts used in the system and a detailed BOM.

More useful than all this perhaps is the comprehensive write-up he provides. This describes the motivation for decisions such as the use of aluminum over steel due to its ability to transfer heat more effectively, and not to use thermal paste due to out-gassing.

While I can almost hear the cries of “not a hack”, the growing use of open source platforms and tool in academia fills us with joy. Thanks for the write-up [Philip] we look forward to hearing more about your laser systems in the future!

HardwareX Is A Scientific Journal For Open Hardware

Disruption is a basic tenet of the Open Hardware movement. How can my innovative use of technology disrupt your dinosaur of an establishment to make something better? Whether it’s an open-source project chipping away at a monopoly or a commercial start-up upsetting an industry with a precarious business model based on past realities, we’ve become used to upstarts taking the limelight.

As an observer it’s interesting to see how the establishment they are challenging reacts to the upstart. Sometimes the fragility of the challenged model is such that they collapse, other times they turn to the courts and go after the competitor or even worse, the customers, in an effort to stave off the inevitable. Just occasionally though they embrace the challengers and try to capture some of what makes them special, and it is one of these cases that is today’s subject.

A famously closed monopoly is the world of academic journals. A long-established industry with a very lucrative business model hatched in the days when its product was exclusively paper-based, this industry has come under some pressure in recent years from the unfettered publishing potential of the Internet, demands for open access to public-funded research, and the increasing influence of the open-source world in science.

Elsevier, one of the larger academic publishers, has responded to this last facet with HardwareX, a publication which describes itself as “an open access journal established to promote free and open source designing, building and customizing of scientific infrastructure“. In short: a lot of hardware built for scientific research is now being created under open-source models, and this is their response.

Some readers might respond to this with suspicion, after all the open-source world has seen enough attempts by big business to embrace its work and extend it into the proprietary, but the reality is that this is an interesting opportunity for all sides. The open access and requirement for all submissions to be covered under an open hardware licence mean that it would be impossible for this journal to retreat behind any paywalls. In addition the fact of it being published in a reputable academic journal will bring open-source scientific hardware to a new prominence as it is cited in papers appearing in other journals. Finally the existence of such a journal will encourage the adoption of open-source hardware in the world of science, as projects are released under open-source licences to fulfill the requirements for submission.

So have the publishing dinosaurs got it right, and is this journal an exciting new opportunity for all concerned? We think it has that potential, and the results won’t be confined to laboratories. Inevitably the world of hackers and makers will benefit from open-source work coming from scientists, and vice versa.

Thanks [Matheus Carvalho] for the tip.

Bookbinding workshop image: By Nasjonalbiblioteket from Norway [No restrictions], via Wikimedia Commons.

Hackaday Prize Entry: Waterspace, A Floating Hackerspace Lab

It’s a boat! It’s a hackerspace! It’s a DIY research platform and an art gallery! It’s Boat Lab!

[Andrew Quitmeyer] lead a project in the Philippines that was nominally charged with making an art and technology space. After a few days brainstorming, four groups formed and came up with projects as wide-ranging as a water-jet video screen and a marine biology lab. What did they have in common? They were all going to take place on a floating raft hackerspace in a beautiful body of water in Manila.

This is a really crazy meta-project, and any of the sub-projects would be worth their own blog post. Even more so is the idea itself — building a floating hackerspace is just cool. The write-up on Hackaday.io linked above is pretty comprehensive, and the “Waterspace” book talks a bit more about the overarching process. Boat Lab is a great entry into the Citizen Science phase of the Hackaday Prize 2016.

But we also love the idea of hackerspaces in non-traditional places. The Cairo Hackerspace is working on a van-based space. And now we’ve seen a boat. What other mobile hackerspace solutions are out there? We’d love to hear!

Continue reading “Hackaday Prize Entry: Waterspace, A Floating Hackerspace Lab”

DIY Vacuum Chamber Proves Thermodynamics Professor Isn’t Making It All Up

[Mr_GreenCoat] is studying engineering. His thermodynamics teacher agreed with the stance that engineering is best learned through experimentation, and tasked [Mr_GreenCoat]’s group with the construction of a vacuum chamber to prove that the boiling point of a liquid goes down with the pressure it is exposed to.

His group used black PVC pipe to construct their chamber. They used an air compressor to generate the vacuum. The lid is a sheet of lexan with a silicone disk. We’ve covered these sorts of designs before. Since a vacuum chamber is at max going to suffer 14.9 ish psi distributed load on the outside there’s no real worry of their design going too horribly wrong.

The interesting part of the build is the hardware and software built to boil the water and log the temperatures and pressures. Science isn’t done until something is written down after all. They have a power resistor and a temperature probe inside of the chamber. The temperature over time is logged using an Arduino and a bit of processing code.

In the end their experiment matched what they had been learning in class. The current laws of thermodynamics are still in effect — all is right in the universe — and these poor students can probably save some money and get along with an old edition of the textbook. Video after the break.

Continue reading “DIY Vacuum Chamber Proves Thermodynamics Professor Isn’t Making It All Up”

Sciencing DVD-RW Laser Diodes

If you’ve played around with laser diodes that you’ve scavenged from old equipment, you know that it can be a hit-or-miss proposition. (And if you haven’t, what are you waiting for?) Besides the real risk of killing the diode on extraction by either overheating it or zapping it with static electricity, there’s always the question of how much current to put into the thing.

[DeepSOIC] decided to answer the latter question — with science! — for a DVD-burner laser that he’s got. His apparatus is both low-tech and absolutely brilliant, and it looks like he’s getting good data. So let’s have a peek.

Laser Detector on 3D Printer Scrap
Laser Detector on 3D Printer Scrap

First up is the detector, which is nothing more than a photodiode, 100k ohm load resistor, and a big capacitor for a power supply. We’d use a coin-cell battery, but given how low the discharge currents are, the cap makes a great rechargeable alternative. The output of the photo diode goes straight into the scope probe.

He then points the photodiode at the laser spot (on a keyboard?) and pulses the laser by charging up a capacitor and discharging it through the laser and a resistor to limit total current. The instantaneous current through the laser diode is also measured on the scope. Plotting both the current drawn and the measured brightness from the photodiode gives him an L/I curve — “lumens” versus current.

laser_curve

Look on the curve for where it stops being a straight line, slightly before the wiggles set in. That’s about the maximum continuous operating current. It’s good practice to de-rate that to 90% just to be on the safe side. Here it looks like the maximum current is 280 mA, so you probably shouldn’t run above 250 mA for a long time. If the diode’s body gets hot, heatsink it.

If you want to know everything about lasers in general, and diode lasers in particular, you can’t beat Sam’s Laser FAQ. We love [DeepSOIC]’s testing rig, though, and would love to see the schematic of his test driver. We’ve used “Sam’s Laser Diode Test Supply 1” for years, and we love it, but a pulsed laser tester would be a cool addition to the lab.

What to do with your junk DVD-ROM laser? Use the other leftover parts to make a CNC engraver? But we don’t need to tell you what to do with lasers. Just don’t look into the beam with your remaining good eye!

Experiments With A Bowden Extruder Filament Force Sensor

We were excited to learn that someone had started working with force sensors on filament extruders, especially after we posted about a recent development in filament thickness sensors.

[airtripper] primarily uses a Bowden extruder, and wanted to be a little more scientific in his 3D printing efforts. So he purchased a force sensor off eBay and modified his extruder design to fit it. Once installed he could see exactly how different temperatures, retraction rates, speed, etc. resulted in different forces on the extruder. He used this information to tune his printer just a bit better.

More interesting, [airtripper] used his new sensor to validate the powers of various extruder gears. These are the gears that actually transfer the driving force of the stepper to the filament itself. He tested some of the common drive gears, and proved that the Mk8 gear slipped the least and provided the most constant force. We love to see this kind of science in the 3D printing community — let’s see if someone can replicate his findings.

 

VHS-Tape-Plasma Mirror Drives Tiny Particle Accelerator

When you think of a particle accelerator, you’re probably thinking of tens of kilometers of tube buried underground, at high vacuum, that uses precisely timed electromagnetic fields to push charged particles like electrons up to amazing speeds (and energies). However, it’s also possible to accelerate electrons in other ways, and lasers are a good bet. Although a laser-based particle accelerator can push electrons very effectively for a few centimeters, they top out at a relatively low maximum “speed” of a couple billion electron-volts, as opposed to the trillions of eV that you can get out of a really big traditional accelerator.

If only you could repeat the laser trick again, “hitting” the already-moving electrons from behind with another beam, you could boost them up to even higher energies. Doing so would take something like a one-way mirror that lets the electrons pass through, but that you could then bounce a laser beam off of. In a fantastic mixture of science and mother-of-invention-style hacking, these scientists from Lawrence Berkeley National Labs use plain-old VHS tape to make plasma mirrors to do just that. Why VHS tape? Because it’s cheap, flexible, and easy to move through the apparatus at high speeds.

The device works like this: a first laser beam passes through a jet of ionized gas and pulls some electrons with it. These electrons are then focused into a beam and pass through some (moving) VHS tape. The electrons punch a hole through the tape. In their wake they leave a hot plasma of mid-90s TV shows you never got around to watching. The second laser beam is then bounced off this plasma mirror and further accelerates the electron beam from behind. In principle, you could repeat this second stage enough times to build up the energy you needed, but for now the crew is working to characterize their single-stage beam. Getting the timing right on the second-stage beam is, naturally, non-trivial.

Anyone who has spent some time in a science lab knows that there are millions of these tiny get-it-done-quick hacks behind the scenes, but it’s nice to see one take center stage as well. If you’ve got stories of great lab hacks that you’d like to see us cover, post up in the comments!

Thanks [Bruce] for the tip, via Science Daily.