open hardware and unconventional electronics john sarik columbia university [email protected]
TRANSCRIPT
About me I have a “distinct speaking style”
I’m a 5th year EE PhD student at Columbia
Hardware hacker in the Columbia Laboratory for Unconventional Electronics
- Led by Professor John Kymissis
- Specialize in “novel integration”
- Entrepreneurial emphasis
• Transistors
• Light emitters
• Photodetectors
• Solar cells
• Piezoelectrics
• Thin film batteries
• Strain sensors
• Actuators
What are unconventional electronics? Conventional silicon electronics are following Moore’s Law and getting smaller and faster
Unconventional electronics are designed for applications with requirements that conventional electronics can’t meet
- Unique sizes or shapes
- Unique substrates
- Unique mechanical, electrical, optical properties
- Unique fabrication techniques
Unconventional electronics will compliment, not replace, conventional electronics
What is “novel integration”? Energy Harvesting Active Networked Tags
- Enabling technology for the “Internet of Things”
Lumiode: A high brightness, high efficiency microdisplay platform
- Enabling technology for head-mounted, see-through augmented reality displays
Silicon TFTsenable high performance circuits at low process temperatures
III-V LEDsoffer high optical power
density, efficient light output, and long lifetime
What is open hardware? “Open source hardware is hardware whose design is made publicly available so that
anyone can study, modify, distribute, make, and sell the design or hardware based on that design.” –OSHW Statement of Principles 1.0
How open is open hardware? Arduino, the most famous example of open hardware has an open source software tool
chain, open source board design files, but non-open components
Literal “black box”
Why is this a problem? Philosophical
- It’s a literal black box
- The “I, Pencil” Problem
Practical
- Limited selection of components and combinations of capabilities
- Worldwide Atmel Shortage of 2011
- Counterfeit electronics are a growing problem
What’s the solution? Replicators!
- RepRap is about making self-replicating machines, and making them freely available for the benefit of everyone. We are using 3D printing to do this, but if you have other technologies that can copy themselves and that can be made freely available to all, then this is the place for you too.
What’s the state of the art today? 3D printers can print a wide range of
materials at different size scales
Currently limited to printing mostly “structural” not “functional” materials
Can we print functional materials? Yes! We can build unconventional electronics using conventional 2D printing techniques
What else can we print? Transistors
Solar cells
Batteries
Displays
Passives (resistors, capacitors)
The most fundamental printable component is a conductive trace!
How do we combine 2D printing and 3D printing? Most hobbyist 3D printers build objects layer by layer by extruding thermoplastics, but there
are currently no functional commercially available thermoplastics
Printing functional materials requires additional hardware!
Wire Extruder [1] Woods Metal [2] Silver Pen [3]
[1] Sells E., Bowyer A., 2004. Rapid Prototyped Electronic Circuits. http://www.staff.bath.ac.uk/ensab/replicator/Downloads/RPEC-manual.doc[2] Bayless, J., Chen, M., and Dai, B., 2010. Wire embedding 3d printer. http://www.reprap.org/mediawiki/images/2/25/SpoolHead_FinalReport.pdf[3] http://openmaterials.org/2010/12/14/diy-printed-transistors-botacom/
What are the current limitations? Software
- Currently limited to printing in a single plane
- Existing software toolchain converts a 3D model to a series of machine codes, but there is no standard for adding functional materials to a print
- Need new file format (STL, Gcode, other?)
Materials
- Limited selection of compatible, available materials
Conductivity (Ω/Sq@25um)
Price ($/mL)
Coverage (cm2/mL)
CuPro-Cote (Cu) 1 0.10 137
Electrodag 915 (Ag) 0.015 15 187
Extrusion Temp
KOH Soluble
Water Soluble
Acrylonitrile butadiene styrene (ABS)
220 No No
Polylactic acid (PLA) 195 Yes No
Polyvinyl alcohol (PVA) 180 Yes Yes
Common Thermoplastics Air drying conductive inks
How do we combine 3D printing and 3D deposition? Research conducted at Microsoft Research Cambridge in the Sensors and Devices Group
Spray deposition system based on a commercial airbrush and room temperature air drying conductive inks
Allows for easy conformal deposition of materials on non-planar, non-uniform surfaces
Overcoming the limitations of spray deposition Object printed in ABS (red)
Sacrificial support and masking layer printed in PLA (blue)
Silver deposited (green)
PLA removed in KOH (ABS and silver not affected)
More complex structures can be fabricated by alternating between ABS, PLA, and silver
Excellent sidewall coverage allows truly three dimensional printed conductive trace
Immediate extensions Fully additive, fully automated printed circuit board manufacturing
Printed electrometrical components
Future extensions Explore new materials such as semiconducting, photovoltaic, or light-emitting inks
Improve the software toolchain and work toward a standard file format
What about stereolithography? 3D printers based on UV curable resins are becoming available
Similar to photolithography, a standard patterning technique for conventional electronics
Different wavelengths of light can be used to functionalize different materials
Can DIY electronics scale? Traditional electronics fabrication requires extremely high yields
3D printed objects can fail in interesting and instructive ways
Printed electronics often fail in frustrating ways
Thousands oftransistors
Millions of transistors
How can we bring printable electronics out of the lab? Leverage the 3D printing and open source communities
Bring together people with different areas of expertise
Conclusion Printable electronics can enable truly open hardware (Turtles all the way down!)
OSCON attendees share a common vision of an open source future and have the skills necessary to make it happen
Questions? Comments? Collaborations? Email me at [email protected]
Demos!