Photolithography PCB Fabrication

PCB Fabrication IllustratedDIY printed circuit boards (PCB) are an intermediate step toward mass producing an industrial-grade integrated circuit.

After prototyping a project using tools like a solderless breadboard, small-run or one-off PCBs are a good choice when you want a more structurally stable version of your circuit that is destined for mass production. Perhaps you would like to be able to install it into a larger project prototype. Once all the what-ifs and tests are successful with these hand-made PCBs, higher resolution industrial processes can be used to fabricate more robust PCBs.

Thanks to members, mirage335 and Dan Barlow, we now have a standardized method to fabricate DIY PCBs with traces (conducting areas) and spacing (non-conductive areas) of 6 mil (0.15mm).

For projects where the 10 mil tolerances made possible by our CNC mill are not enough, photolithography is a good alternative. The process uses light-sensitive coatings to mask conductive surfaces before etching. The result is a a lovely printed circuit where before you had a jumble of wires. The process, workflow, and references are described by mirage335 on our wiki.

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Biosignal Amplifier Ready for Plug-and-Play

Mirage335 Biosignal Amp Host Schematic (detail)HacDC’s biohacking group has developed a new, ultra-low-noise biosignal amplifier and released it under the GPLv3.

The Mirage335 Biosignal Amp makes brainwave (EEG), heart (ECG), and muscle (EMG) detection all possible without reconfiguration.

Mirage335 Biosignal Amplifier Setup

Lead designer, mirage335, writes:

This system is geared for maximum performance close to theoretical limits. Ideally, the lower noise floor allows us to confirm the presence or absence of weak biosignals, especially electroencephalography signals, when they become difficult to detect with other systems.

Analog (direct-to-scope) and USB (direct-to-computer) outputs are provided. USB functionality is provided by an Arduino compatible ATMega32U4 and LTC2440 24-bit Analog-to-Digital converter.

EEG and ECG (Wikimedia Commons)

    Other features:

  • USA companies provide all parts, including circuit boards
  • Safety oriented architecture. Multiple isolation barrier and surge suppressor layers.
  • Active electrodes, wet and dry designs.
  • Extreme common-mode rejection measures.
  • Lowest noise amplifiers, based on new thermal noise research.
  • Future proof. Modular SATA data cable architecture provides smooth upgrade paths.
  • Isolation amplifier. Safe, high-resolution analog output for lab equipment (eg. oscilloscopes), sound cards, microcontrollers, and ADCs.
  • USB support, based on ArduinoDAQ (ATMega32U4 + LTC2440).
  • Efficient, high-order IIR biquad filters notch out 60Hz, 30Hz and high-frequency noise, right at the embedded microcontroller.
  • Wide supply voltage support. +/-6V to +/-15V
  • Resistor programmable gain. 13000x default.

Mirage335’s effort was supported by these members of our biohacker group, contributing to the design, testing, and funding of this versatile device:

  • Shawn Nock
  • Sharad Satsangi
  • Stuart Washington
  • The Real Plato
  • Logan Scheel

Usage instructions are available on the wiki.

Complete schematics, PCBs, BOMs, 3D printable enclosures, firmware, USB driver software, and documentation hosted on Github:

Additional documentation is available on the project’s webpage.

Join the HacDC biohacking community’s mailing list: https://groups.google.com/a/hacdc.org/forum/#!forum/meat

Support HacDC When You Order From Amazon

Support HacDC when you buy from Amazon.com By using our Amazon Affiliate link (especially during the impending synchronized gifting season) you can contribute to HacDC every time you order from Amazon.com. This will set a cookie that will persist for 24 hours or until you use another organization’s affiliate link.

If you want to always donate a portion of Amazon.com purchases to HacDC, a browser plugin (Firefox | Chrome) can automate this for you and make it permanent until you change settings or disable the plugin. Use tag hacdc-20 in the plugin settings for USA.

This is not an endorsement of Amazon.com over other on-line retailers. Shop around for the best deal or shop at stores you’d like to support. If you choose the latter, you can still donate to HacDC in other ways! :)

NPR Segment on ArduSat features HacDC Summer School!

NanoSatisfi's ArduSatHacDC’s Summer School 2013 was featured a few days ago in a NPR story by Geoff Brumfiel about the upcoming ArduSat launch. ArduSat is an Arduino-enabled satellite that you can buy time on to run your own Arduino-powered extra-terrestrial experiments that make use of the nanosatellite’s “STANDARD sensor package.” Read more about it and listen here (includes workshop photographs by NPR’s Heather Rousseau):

Tiny Tech Puts Satellites In Hands Of Homebrew Designers

ArduSat image 2013 © NanoSatisfi, Inc