the 20 cent “paperfuge” – Biohacking ist ein Kinderspiel

Das Jahr 2017 fängt schon cool an. Im Jänner machte ein Video einen viralen Rundgang durch die Science-Szene und preiste eine “centrifuge for 20 cent”an….ich so, whaaaat? Was ich anfangs für einen Hoax hielt stellte sich als eine ziemlich geniale Idee heraus.

Wer von euch kennt das Kinderspiel wo man mit einem Knopf und einer Schnurr mit bisschen Geschick zum Surren brachte? Ich weiß noch, dass ich es im Kindergarten mal probiert habe und auch meine Großeltern noch mit diesem Spiel aufgewachsen sind,…man brauchte immerhin nur einen Knopf und ein Stück Faden. Man hält die Schnurr an beiden Enden mit den Händen fest während sich in der Mitte der Knopf drehte, sofern man im richtigen Moment an den Enden zieht.

Bioengineers aus Stanford haben dieses Kinderspiel weiterentwickelt und daraus die “Paperfuge” gebastelt. Ein Hand betriebenes Gerät mit einer Scheibe anstatt dem Knopf, welches Leistungen von 120.000 rpm (rounds per minutes) schafft,…die übliche Tischzentrifuge im Labor schafft 14.000 rpm.

 

Wahnsinn, eine tolle Idee, denn viele schnelle Analysen über Infektionskrankheiten benötigen Zentrifugen als Arbeitsschritte, wie z.B. die Trennung von roten Blutkörper und Serum. Aber was tun, wenn man weder Strom noch die passende Ausrüstung dafür besitzt? Diese Pagerfuge könnte dafür die Lösung sein.

 

Welche weiteren Einsatzmöglichkeiten, außer Blutproben, diese revolutionäre Erfindung noch hat möchten wir im OLGA heraus finden und haben uns selber dieses Gerät gebastelt.

pagefuge

 

 

Erste Versuche mit einer Bakterien Zellsuspension sind vielversprechend. Nach ca. 5 Minuten “spielen” wurden die Zellen am Boden eines 0,2 mL Reaktionsgefäßes pelletiert.

cell pellete

Neben unterschiedlichen Modellen, Formen und Größen kann man noch das zu zentrifugierende Volumen als auch die Art der Probe versuchen zu variieren,…es gibt also noch viel auszuprobieren. Im Labor haben wir viele Arbeiten, welche Zentrifugationsschritte benötigen (DNA-Isolierung, Proteingewinnung, schlichte Abtrennung von Zellen aus Lösungen, usw.) und ich kann mir gut vorstellen, dass, wenn die Paperfuge sich experimentell als qualitative Alternative zur üblichen Tischzentrifuge heraus stellt, dies für viele Analysen-Labore in Entwicklungsländern eine günstige, Strom-unabhängige und schnelle Hilfe darstellen kann. Das Potenzial ist hoch, genau wie die Motivation :D

Beispiel der praktischen Anwendung eines 3D-Druckers

„Schnell, schnell! Wir brauchen noch ein wunderbares und nicht käuflich erwerbbares Geschenk für Mama, Papa, Opa, Oma und meine 2 Geschwister. Alles individuell auf die jeweilige Persönlichkeit zugeschnitten.“  …tjaaa, da wird’s meistens schon etwas eng mit der Geschenks Auswahl.

Aber zum Glück sind viele Leute kreativ und können sich dafür etwas ausdenken. „Heureka!“, ruft dann der erhellte Geist und verweist einem auf den Vorschlag, man könne doch kleine Skulpturen der jeweiligen Lieblingstiere schenken (ich selber sammle seit Kindesalter allerlei Figuren von Schildkröten). „Super Idee, Gehirn. Aber wie soll ich das anstellen? Wie soll ich meine Idee in die Praxis umsetzen?“

Und hier kommt der Realraum ins Spiel! Hackerspaces dieser Art sprühen geradezu nur von Kreativität und Handlungsdrang, vor allem wenn sie so gut ausgestattet sind wie wir ;)  Ob Holzgeschnitze, sämtliches Gedrähte (also Draht) zum Biegen und Löten, dünne Holzplatten, verklebbare Teile oder individuelle Kunstwerte aus Plastik,…mit unserer Werkbank, dem Lasercutter oder dem 3D Drucker sind die Möglichkeiten mannigfaltig. Wer noch ungeübt ist mit dem Umgang jener Gerätschaften kann sich natürlich Hilfe von den Mitgliedern holen, besser 3x nachgefragt als 1x kaputt gemacht.

So hat man schnell das passende Geburtstagsgeschenk gefunden, in dem Fall mit dem 3D-Drucker selbst erstellt. Wer der Meinung ist, wenig Zeit oder nicht kreativ genug dafür zu sein (so wie ich :P ) kann sich genug Models und Vorlagen aus dem Internet holen.

davdav

LaserAccess Updated

DSC_5315

Updated the Laser-cutter access control box today. Major changes include.lasercutter_zeit_und_karte

  • Now features a big flat space that will happily hold your RFID access card, token or whole wallet. No more fumbling and trying to get a card to stick to the side of the box
  • Dedicated holder for USB-sticks, the laser-cutter key and the focus distance measurement spacers.
  • Dead-Person-Button – remaining time indicator lights are more diffused by the cover and thus more muted.

The basic logic remains the same.  Once you went through the laser-cutter introduction and got access, just put your RFID token on top of the reader. The beep and the green bar indicates the laser is now hot and you can start cutting. Press the DeadPersonButton while the bar is still green to indicate you are watching and realraum hasn’t burned down yet. Remove the card when you’re done. Beeps and blinks will indicate that laser is now being disabled.

See the wiki for more.

Was lange währt, hängt endlich gut

wpid-dsc_5292.jpg

Not long after realraum moved to it’s current premises, we knew we wanted a curtain in the front windows, just like in the old realraum. Not only to better use the beamer during the day, but also to keep the room cooler in the summer and have a tiny bit more insulation in the winter. There was also hope of it dampening echos and loud noises.

That was about 2 years ago.

finally some sturdy wood
finally some sturdy wood

But how to hang the curtain. The ceiling after all, does not bear any loads. The search for a solution that would allow us to move the curtain freely over the ranges of a 4 and 5 meter wide front window began. The old curtains were both too short and not enough. Where to get nice looking fabric cheap, that is both fire retardant and thick enough to insulate was also an open question. Of course such fabric would be heavy and did I mention the ceiling does not bear any loads.

Now enter a handful of engineers with dwindling spare time, different opinions and varying expertise into the mix and you may begin to see what took so long.

one of two long pipes
one of two long pipes

Quite early, we agreed that spanning two extremely sturdy pipes from one wall to the column to the other wall was the solution to go with. Eventually Christoph procured one for us which was a bit thicker than anticipated. Somewhen, frequent visitor and hobby seamstress Sasa managed to get us between 200 and 300 m² of great fabric for a bit over a 100 Euros. Thank you Sasa for making them into curtains and even putting in the eyelets.

Some very motivated members promised to mount the pipe but went to work more quickly than anyone had anticipated. Miscommunication happened, some mistakes were made. Finally we re-mounted the pipe three times.

zip-ties a smooth sliding curtain not make
zip-ties a smooth sliding curtain not makes

The first attempt had to go because the wood holding up the load was too thin. Instead of the planned U-cut to hold the pipe, an easy V-cut was made. The pressure exuded on the panel in direction of the fibres caused the wood to crack pretty early on. Then, instead of moving away the cable conduit (which later, turned out to be really easy to do), a daring constructions of wooden distance holders bridge was built in order to mount the pipe-holing-wood on top of the cable conduit. While not very tidy, the real problem here was that the screws were too long for the holes drilled. (Understand: were talking about a massive and solid concrete column holding up the whole house. Even with the right equipment that doesn’t drill easily).  Consequently there was an air-gap between the column and the wood holding up the pipe. As we all remembered that day: screws hold stuff in place by way of static friction, i.e. pressing one material onto another e.g.. by pressing a piece of wood against a wall. They are not meant to withstand orthogonal forces and do not like to bear loads that way. Christian was the first to spot the air-gap. Exasperation and learning followed

should brear a few hundred kg
should bear a few hundred kg

Eventually, the sturdy, thicker than what your normal hardwarestore sells, wood we wanted to use in the first place appeared and the pipe-holders got completely redone. Sturdy enough to hang a small car on it. Or, you know.. a curtain and some people that might stumble into it during a party. Gotta plan for everything.

Finally, the pipe was not sufficiently secured against longitudinal movement. Meaning the direction in which you would pull when you move the curtain. Too much and the strings holding it in place might rip and crash everything down. Thankfully Christian also finally drilled holes at the ends and secured them with bolts across and through the pipe.

Don’t exhale yet, we’re not done.  The curtain still had to be mounted, and guess what. Curtainrings that fit a 42mm diameter pipe are really really hard to get. We tried to make due (thanks to Sandra for all the work), it’s really hard to move a curtain that is hanging on 150 tightly bound zip ties. Eventually we found a German shop that sells big metal rings at a surprisingly reasonable price and ordered right away. I don’t even want to explain why it then took 3 months for them to arrive.

Yesterday, then, the long road had an end, the project finally got done. Our junior member David took up heart and down the pipes, replacing the zip-ties around the pipe with well moving (and sounding) metal rings.

no more sliding rods
no more shifting rods

So end of story. Finally. Or is it? Because we also ordered clips to hang the curtain from it’s eyelets to the rings. We ordered new eyelets with a bigger inner diameter because the clips would not fit in the very small ones we had when Sasa and Sandra put them in. (Never believe the online-shopping product description). Right now the curtain and the clips/rings are still connected with zip-ties. So the question remains… do we still care? Or did anybody even read all the way down?

Light in realraum is now faster

licht.realraum.at, went FTLw today. That is… it became much Faster Than Last week. :-)

Since the Raspbian image upgrade and move to a bigger (but slower) SDcard, licht.realraum.at had become truly sluggish. To the point that pressing a button to turn on the light or change the stereo volume could take up to 6 seconds until something happened. (Obviously we disabled the swap-file long ago.)

The problem was quickly identified. Processes don’t load quickly enough.
The fact that the whole systems was a dunghill of bashscript cgi-scripts and python helper scripts also did not help. At all.

First attempt to rectify this: rewrite the python helper rf433ctl.py. Formerly it was a simple script that would be called by the cgi-script and send the appropriate bytes down to the teensy.
Each call to it, however now took forever. So. I rewrote it as a daemon that would constantly stay in memory and be nudged by other instances of it via RPC. The idea being, if it’s already completely in memory, loading a second instance should be faster. Right? Wrong!. Unfortunately that did not work out at all.

Second attempt to rectify this: Remove the kiosk functionality and thus memory-hog midori from licht. Thankfully a very nice person gifted us a RaspberryPi per (almost) anonymous letter, so we had the necessary hardware on-hand to split the functionality onto two separate boxes: licht.realraum.at and smallkiosk.realraum.at
Unfortunately, even freeing up 60% of memory did not even put a dent into the problem.

So.. third and last attempt. Hit it with go ;-> In a 3 hour session, I rewrote the whole dunghill as a monolithic golang daemon/webserver/tty-handler which, once loaded, always stays in memory. Then I got rid of lighthttpd and the python scripts. Result… Speedup from 6s to <=0.05s !! Should have done this right away really…

made with ♥ in realraum

madein

Some of you might know this little signs saying “Made with ♥ in San Francisco” (or similar) on the webpages and gadgets you love. We also make stuff with ♥, not all of it digital, so we made our own sign. :-)

If you feel like it, you can use our sign – our make your own. You can find the used file in our logo git Repository on GitHub. (By the way, we use the Cagliostro font for our logo.)

Wichtel Lamp

lampe4 lampe1 lampe2

Although not a big fan of Christmas, tradition, and Christmas tradition, Stefan used the realraum nightshift to build a lamp as a Wichtel present. The lamp features a mountain on the front side, which is lit from the inside by some simple LED setup. Furthermore, it is able to change the color of the light via an IR remote.

The process of creating the lamp involved vectorizing the image, lasercutting the pieces, rasping some small errors, soldering and glueing of all the things! So basically all important parts of realraum‘s infrastructure were used in building the lamp. ;-)

lampe3 lampe5

Special thanks to erdbrbl, equinox and xro for their assistance, guidance, and teaching me how 2-components adhesive works.

Keeping things organized

Wood with holes drilled in

Where do you keep all the cables in your lab? Maybe you zip-tied an old rake to the wall and repurchased it to hold your twisty coils? Thinks it may be time for a cleaner solution? Wood, Drill, 3D-Printer and half an hour of time, to the rescue.

One of the oldest tricks in the book: drill a few holes into which to stick your lab-cables. Screw in a few screw to clip your clips on. Use a bit of pliable wire to create holders for your test prods, and voilà: a tiny bit less chaos :-)

Our trusty TAZ4 even takes us a bit further, spitting out a nice custom made BNC-cable holder.

 

BNC Holder, printed with TAZ4