Wild openQCM
Astrophysistis from Novaetech S.r.l. made open hardware a quartz crystal microbalance - http://openqcm.com/
"QCM could be used as a tunable gas sensor and for monitoring the aerosol deposition in ambient conditions. The applications in liquid environment show enormous potentiality. QCM is very effective in measuring binding events on functionalized surface, such as antigen-antibody binding and protein-protein interactions. It is a powerful tool in life sciences, being able to sense DNA hybridization and specific drug compounds."
if you know how to make thin film deposition... (not part of the open project)
The website provides a download for the software, electronics and 3D printed parts as well as some information and nice pictures on the technology...
Contents
General Info about QCM
DIY Build
lets build one - see if I find all the materials needed in my lab or stores around the corner (highest level open hardware check).
The crucial part beeing the quartz crystal oscillator Ryan George contributed the perfect hack: "you could always take the crystal out of a timer..."
| quartz crystal oscillator
ahh, you can also buy the sensor from the openQCM store for 14 euro... reasonable.
| Fun With Crystal Oscillators
Choose an oscillator like this, openQCM uses frequencies of 6MHz and 10Mhz. You can get them here for 0.60-1.00 € reichelt.de
I did it. Never knew what was inside these devices - amazing hack.
We just need to find an easy way to open that little can. Maybe can be kept as housing with drilling two holes for gas in and outlets...
Downloaded 3D files, electronics, BOM, Software. Everything here and looks ok. 3D files are not design for simple 3D Printer (lot of overhang) some simple laser cut parts would be better... Overall the project looks quite straight forward and the source files are easy to find and of good quality. Naaice.
While the 3D printer is printing the case, lets run the openQCM software from an arduino UNO with the hacked sensor...
Download and install is easy, you need to install the | FreqMeasure Library in your arduino library folder.
depending on what board you have the frequence (sensor, SIG) input pin changes, see list on FreqMessure site. For Arduino UNO it is pin 5.
Power to the oscillator and connect output pin 3 to arduino pin 5. Start the openQCM software and here we go...
Hit connect and search for port in the bottom right of the openQCM viewer.
Result when spitting on the sensor - is this what I am supposed to get...
Conclusion
So far, quite easy hack. Did it in less than 2 hours with only material from the Lab. The temperature sensor can be connected to analog pin A1 of the arduino - did not get any reading from this, hmm...? Maybe make a nice bread board setup, find an easy way to connect tubes. All other (3D printed) parts Beigemüse.
Guess now we need some bioactive coating...
some background about bioactive surface coatings
My slides about the topic, partly in german:
And a great overview of the field
Kasemo, Bengt. 2002. “Biological Surface Science.” Surface Science 500 (March): 656–77. doi:10.1016/S0039-6028(01)01809-X.
File:kasemo_2002_biological_surface_science.pdf
Video from q-sense