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NanoBlog

A blog about anything nanotech

Innovation, complexity, and system engineering

morreale Monday 22 of November, 2010
The November 1/8, 2010 Aviation Week & Space Technology issue on innovation and the article on revamping system engineering have struck a nerve with me. The article describes high profile program failures in aerospace and defense, like the integration issues with the F35 and the manufacturing issues with the 787 as a problem with present methods of system engineering. Systems have become so complex that the Apollo-era system engineering approach that breaks systems into subsystems and defines the interfaces between those subsystems is no longer adequate today according to the article. Further, complexity measurement, elegant design, and graceful performance outside the performance envelop are now important design criteria in modern systems design. DARPA has funded the META program to address these issues through the development of a modeling language so that companies can model before building a system. It’s an ambitious project and I hope that its use becomes widely available for use across many industries.

Star Trek and Systems Engineering
So I have to admit that I’m a long time Trekkie or Trekker or what every it’s call now a days. I watch Star Trek any time it’s on. I can’t just look away. It gave me a constructive model of how all kinds of different creatures can work together, which has influenced my professional work life. Expect this I did not. It was socially progressive for its time too. The engineering and adventure are my favorite aspect of the show. So, I love the show but parts of the show frustrate me. Scotty, Geordi, and Data, for example, could rig together vastly different parts and systems together to perform new functions that the original pieces were never designed to do in the first place. The team could create these systems in almost no time and under high pressure situations. The new system would work flawlessly, precisely, and save the planet without any apparent testing before hand. Anyone who has done any kind of design before from flower arranging, to painting, to circuit design, to aircraft or auto design on this planet knows that it’s not that easy. Today, the materials or components have to be just right. The resulting systems have a narrow range of operation and it takes several prototype iterations to get a system to function reliably and precisely. Outside of the intended operating range, present day systems don’t perform well and are more likely to fail than not perform. They also don’t perform well when a component fails. The fault performance isn’t graceful either (It’s dead, Jim). Designers may spend a lot of time modeling and simulating the design but models don’t capture everything. The first prototype gives you an idea of the general performance and a start at understanding the dynamic behavior of the system.

Real World Integration Issue
In the mid 1990’s for example, I worked on a multi-gigabit per second multiplexer for a telecom system. The system went into production and then into service. Then we discovered that every once in a while bits would get dropped when switching from the operating input to the backup input when the operating input failed (at least 1 out of ~10,000 times). Since the system rarely switched due to the inherent reliability, it took a while to see this problem. It took about a year of tuning firmware, adjusting Phase Lock Loop (PLL) bandwidths, and adding a PLL before the problem was solved within our equipment. The solution to the problem transcended subsystems and interfaces, which typically are the root of most problems. Then the interoperability tests began with equipment from two other companies. Strangely, the ITU specifications on SONET equipment and timing does not adequately define the dynamic switching behavior of these types of systems. At the beginning of the project, I did not expect this issue or that it would lead me to spend seven wonderful weeks in France working with an international team to identify the root cause of the dynamic switching failure and determine a fix to allow all three systems to interoperate without fault (no faults in many 100,000s of switches). Even now, it’s not clear how to model, simulate, prototype, integrate, and test for dynamic (or now emergent) behaviors for complex systems when you don’t know what these behaviors might be or how it occurs across subsystems and interfaces. At the time, the cost of the simulation tools and models to model the whole system might have cost more than the system itself.

Operating Outside the Envelope
The other challenging issue is designing systems to work gracefully outside of their operating envelope and to fail gracefully. I worked on a hi-rel pump laser power supply around 2004. The circuits were modeled in SPICE to get a first cut at the design. I could not get SPICE models for all the semiconductor devices so simple substitute models were created as a workaround. Once you identify candidate devices for a design, you study the datasheet. Each vendor has a way of writing datasheets and it takes some experience and testing to understand what the datasheet is telling you. The datasheet doesn’t always tell you the sensitivity to various parameters so the full “personality” of the device can’t be understood from the datasheet. Simulating the circuit can include some tests for component failures but conclusive results can be difficult to obtain because the component models may not capture the fault conditions under test, or SPICE may not converge. I’ve tested the board by examining the behavior of the design when passive components fail open or short. For designs with under a hundred components, this may be reasonable, but not for designs with 100s or 1000s of components. The open and short failure mode tests were made with the same methodology used for the way the reliability analysis is usually computed. No attempt was made to determine what happens if a resistor value or capacitance value changes over time. The number of combinations to test becomes too large to test in a reasonable time.

Nano Quantum System Engineering
As someone working on a nanodevice, I am thinking about the device design, tools, techniques, methods, verification, and integration of the device into a system. I fall back on the subsystem-interface approach as a matter of reflex but since nanodevices function at the quantum level, these techniques do not seem adequate or even applicable. I wonder what system design tools that incorporate hundreds or thousands of nanostructures and devices would look like. Perhaps my favorite Star Trek engineers were able to succeed because their tools were so good at making all the pieces work together. Perhaps, someone like DARPA will create programs to produce quantum mechanical-based system design tools to design complex nanoscale systems. This might gets us closer to the future we envisioned in 1966.

Magnetism: From Fundamentals to Nanoscale Dynamics

morreale Saturday 13 of November, 2010
This book is awesome. Professor Stohr gets very high marks in the way he easily explains magnetism, electromagnetic fields, and quantum mechanics. I like the way he takes a historical prospective in describing the subject matter. He also describes the methods by which problems are solved and some of the limitations associated with these methods. I have not seen this approach before. My only criticism about the books is that his summaries of laws that a section is based on like Gauss theorem for example are a little terse, but I accept this because other wise this 820 page books would be inconceivable long. I have not taken a course in quantum mechanics so I've been using Feynman's Lectures on Physics to help fill in some of the gaps.

SCPD Nano course enrollment deadline December 20, 2010

morreale Wednesday 10 of November, 2010
The Winter semester is nearing at the Stanford Center for Professional Development (SCPD). The Winter 2010-11 course schedule has been posted and the the deadline for registration is December 20,2010. These are graduate level course that can be taken as part of certificate program in a number of fields. I would guess material science or electrical engineering would interest most readers of this blog. Several course to consider include:
  • EE336/MATSCI346 Nanophotonics (ECE695s Nanophotonics from Purdue was developed with Stanford in 2006 and is available on-line for free)
  • EE237 Solar Energy conversion
  • XSUST133 Energy Storage and The Hydrogen Economy
  • XSUST134 Hydrogen Utilization - Fuel Cells
  • XSUST132 Photovoltaics
For those interested in entrepreneurship check out

NDA's and Inventions

morreale Wednesday 10 of November, 2010
I'm a bit troubled but this new revelation after attending the Independent Inventors Conference at the USPTO last week.
  • Many countries have an absolute novelty requirement so if you make a public disclosure about your invention, then you would not be able to get international patents.
Now, I ran across Brad Feld's interesting posing on How to Create a Sustainable Entrepreneurial Community and followed links to his new book Do More Faster. One of the authors in the book states that he does not sign NDA's when talking to entrepreneurs. I can see why because the are a pain and you can sign a lot of them in the course of doing business. I have also experienced the same thing from VCs (i.e. won't sign an NDA). Now here's the rub. Without an NDA, you make a your invention public and thus forfeit the chance to obtain a foreign patent. The NDA offers protection from public disclosure. At least in the US, you have 12 months to file for a provisional or non-provision patent from the first public disclosure to preserve your invention rights. It is my hope that VC, angels, and other will be more willing to sign NDA's to protect the future value of an invention.

Inventors resources

morreale Sunday 07 of November, 2010
The Independent Inventors Conference at the USPTO provided a wealth of information on organizations that provide support to independent inventors. Some of these organizations include:

Independent Invertors Conference

morreale Sunday 07 of November, 2010
US Patent and Trademark Office held their 15th Annual Independent Inventors Conference in Alexandria, Va last week. It was an informative and interesting 2+ days of talks and breakout sessions. I was able to sign up for a one-on-one with a patent examiner to discuss some specifics of my ideas that may be patentable. Overall, I learned that patenting an invention is way more complex that I imagined but the USPTO will take every effort to help independent inventors through the patent process. Your patent description plus claims still has to be proper and legally correct which shouldn't be a surprise. I recommend attending next years conference if you have any interest in patents or meeting fellow inventors. Now to begin that search for prior art and begin that market study.

Making Stuff mini-series

morreale Wednesday 20 of October, 2010
Nova will be showing a four part mini-series on Making Stuff starting January 19, 2011. Nova has a Preview of the show that looks very interesting. I did not expect the adventure and exploration aspect of the show but like the idea. It reminds me of Scientific American Frontiers shows with Woody Flowers and Alan Alda. The series was produced in cooperation with the Materials Research Society (MRS). I recall the announcement of the series at the 2009 Fall MRS meeting and expected it in the fall of this year. I'm eager to see it.