Team:Madrid-OLM/ProManufacturing

Madrid-OLM

Manufacturing Protocols

Manufacturing Protocols

Texto de explicacion/ resumen de la pagina.

Chip

1- Mold making

  • Laser engraver hacking

    Laser engraver hacking

    Bill Of Materials: You could see a complete BoM here (upload the bill).

    Amount of time: 3 hours.

    Total costs: 100 €.

    The laser usually come with a proprietary software that only allow you to engrave images. As the chips are going to be cuttered as a vector we’ll need to install a new laser firmware (into the laser) to be controlled with other software (into the PC connected to the laser).

    1. Check if your laser could be directly flashable (flash = installing the new firmware) in this link.If the answer is yes, skip to the “software workflow” step. If the answer is no, just continue reading.

    2. When the Arduino UNO and the CNC Shield with the drivers arrive, substitute the old electronics of the laser with the new ones following the tutorial of the previous link. The software that you will need to follow this tutorial will be:

      1. The official Arduino IDE that you could find in their own page.

      2. The open-source laser firmware (GRBL). You could find the version that we have used (v1.1) in our GitHub repository.

      3. TThe program which control the laser and is going to send the designs from the PC (Universal GCode sender). You could find the version that have worked with us in our GitHub repository (same link as the previous step).

      CAUTION: We have uploaded a different version of the laser firmware to the one described in the tutorial. The only connection that you have to do differently is connecting the laser to Z+ pin instead of SpnEn.

      Disclaimer: The programs that we have used in these step are not developed by our group and are hosted in our Github just to keep the version that have worked for us.

  • Software workflow

    Software workflow

    Bill Of Materials: You could see a complete BoM here (upload the bill).

    Amount of time: 2 hours.

    Total costs: 0 €.

    1. You only need two applications to run your laser engraver:

      • Inkscape (for creating the design and and the.gcode file). A .gcode file stores the required machining orders for the laser to cut the designed geometry.

      • Universal Gcode Sender (send the .gcode file to the Arduino).

    2. In order to create the shape of your microfluidic chip, you need to have a feasible design. There are many open software applications, as:

      • DraftSight (2D): although you could design directly with Inkscape, an specific software for design may result handy at some point of despair.

      • Freecad (3D).

      CAUTION: Alternative versions of a .dxf file will not be imported successfully.

    3. If the design is made in a software different to Inkscape, you should export the file as a .dxf file (R2013). Inkscape can import this sort of files.

    4. Once the design is created and imported into Inkscape, you should place it within the canvas with the required proportions. For NEJE laser engraver, the dimensions of the bed is 38 x 38 mm. You should find how Inkscape work area relates to the effective area of the bed.

    5. Once the dimensions have been corrected and fixed, you should convert the lines to a “path” format, clicking in the “path” tab and selecting “stroke to path”. We have tried to omit this step, and it seems it does not matter skip this step.

    6. Click on “extensions” tab and select “generate laser gcode”, and set the cutting parameters. These parameters should be set experimentally. Speed, laser power, passes vary depending on the specific tape selected, or the surface where you stick the tape. We encourage you to set your desired parameters, based on your specific scenario.

    7. Once the .gcode file has been successfully created, open the Universal Gcode Sender and and set the ports and baud rate (115200 bps).

    8. Now you need to set your “Zero machine coordinates”. From “Machine control” tab, move the X- and the Y- to the coordinates that you want to set as (0,0). And click on “Reset Zero”

    9. Import the file. (File mode tab -> Browse). And finally send it to the laser engraver.

  • Calibration

    Calibration

    Bill Of Materials: You could see a complete BoM here (upload the bill).

    Amount of time: 2 hours.

    Total costs: 10 €.

    There are three factors that you should consider for calibration purposes:

    1. Choosing the tape: Depending on which depth of channel suits your needs, you should choose one tape or another. Cutting parameters should be established by each user, according to their particular needs.

      2. ADVICE: We are using brown packing tape. The deep of the tape is 50 microns and the parameters that have fit to us are the following: Travel Speed 200, Laser Speed 50, Laser Power 12000, Power-On Delay 0, Passes 2, and Pass Depth 1.

    2. Calibrating the dimensions of the Inkscape canvas: we highly recommend you to know the correction factors to apply to your design. A good practice should involve (for instance) designing a 10 x 10 mm square in Inkscape and send it to NEJE laser engraver, and measure it afterwards to know exactly how dimensions translate between software and manufacturing hardware.

    3. Getting to know the effective work area of bed of the NEJE laser engraver: if you set the laser over the Zero-machine coordinate, and the, in the “command tab”, you insert the command s01, and M3, you should see how the laser turns on. If you click on X+ or Y+, you should be able to navigate over the edges of the bed, and thus, determine (and engrave) them onto the bed or any other surface that you might consider.

    Disclaimer: The programs that we have used in these step are not developed by our group and are hosted in our Github just to keep the version that have worked for us.

  • Cutting

    Cutting

    Bill Of Materials: You could see a complete BoM here (upload the bill).

    Amount of time: Depending on the project

    Total costs: less than 5 €.

    Although cutting is a pretty straight forward process, please, take this advises into consideration:

    1. Mind your eyes: Please, do not hesitate to use the safety glasses devoted to look to the laser.

    2. Use your final polymerization surface to support your tape: we have used an acetate sheet that fits in our final polymerization chamber. Ensure your surface are horizontal and without bubbles between the tape and itself. Lifting off the table from the surface in which it has been cuttered may cause the deformation of the original pattern.

    3. Chlorine content in many tapes: As many tapes contain a remarkable amount of chlorine, we advise you to cut in a ventilated place and to avoid inhaling this.

    4. Enjoy not always you get the results that you are planning. Take the time to set your arrangement and enjoy this process!


Back to Mold making Index

2- PDMS casting

  • Preparing PDMS
  • Making a vacuum pump and vacuum chamber
  • Degassing
  • Polymerization process


Back to PDMS casting Index

3- Plasma bonding

  • Modding a microwave
  • Calibrating the microwave
  • Baking the PDMS


Back to Plasma bonding Index

4- Closing the microfluidic circuit

  • Choosing the pump, the tubing and the connectors
  • Troubleshooting the leaks


Back to Closing circuits Index

Assemblies