Niels Nielsen, Gonzo Engineer
An Overview of Vapor Explosion Physics in Thermal Inkjet (TIJ) Printheads
ECI International Conference on Boiling Heat Transfer
Spoleto, May 7-12, 2006
Abstract: A thermal inkjet (TIJ) printhead puts individual dots on paper on demand by using microscale superheat
vapor explosions to kick droplets of liquid ink out of tiny nozzles. This boiling mode- on-demand, discrete vapor
explosions- furnishes the physical basis for the entire field of thermal inkjet printing (a business worth tens of
billions of dollars a year worldwide). The working fluid in the “TIJ boiler” is the ink itself. A TIJ printhead of
modern manufacture contains as many as 3900 such boilers, one for every nozzle in the printhead array. The
boiling regime required for this application (extremely high superheat, heterogeneous nucleation of local boiling
at atmospheric pressure) is unique in the field of boiling heat transfer as is the microscopic scale lengths and
sub-microsecond time scales that characterize it.
Printing Enters the Jet Age: How today's computer printers came to eject microscopic dots with amazing percision
Invention & Technology, Spring 2001
In the firest few decades of digital computing, the output of printed information to the user was essentially an afterthought. Typewriter-style impact technology, in which a piece of metal in the shape of a letter was struck against a ribbon, remained virtually universal.
My Favorite Consellation
My favorite constellation is Orion, because it’s got Betelgeuse in it. That’s the bright, reddish star that represents his left shoulder, and is my favorite star in the night sky. It was named by the Arab astronomers during the Dark Ages. Back then, the Arabs were building libraries and inventing stellar navigation while the European kings were clubbing each other over the head with big sticks and entertaining themselves by learning how to write their own names. Betelgeuse is the only star (besides Our Mister Sun) big enough and close enough (450 light years, give or take a few) to actually show as an extended object in photos taken by the Hubble Space Telescope. And it is a VERY SPECIAL STAR. Here's why:
A Gonzo Engineer’s Take On How To Manage An Engineering Project
While trying to write something at work which was beginning to look more and more like a grant proposal, I started running through my mind how I would run the project, if it came to that, and I drew up a list of things that define the Gonzo Engineer Program For Engineering Success. And here it is!
Slim Volume’s Take On Physics, Part One:
Why There Is No Magic In This Particular Universe
Magic lets you have your cake and eat it too. It lets you deposit a penny in your checking account and then withdraw a billion dollars. It lets you move mountains without moving a single muscle. It conveniently places a conveniently razor-sharp sword right in your hand when all you were armed with a moment earlier was a restraining order printed on a thin and significantly less sharp piece of paper. It lets you run the hands of the clock backward, go as fast as you want, fly like a bird, get out of jail free, and so on.
To All The Members of The Original St. Helens/Vesuvius Project Team
Greetings from Niels Nielsen in Corvallis. March of 2014 marks the 30th anniversary of the introduction of the ThinkJet printer and St.Helens printhead. At the time I was working on testing and tuning the St.Helens printheads in our mop closet lab in Corvallis back in 1981, I had absolutely no idea that this product would start a revolution which fundamentally redefined the marketplace for printers, and firmly established HP as the undisputed world leader in that market. Neither did I in my wildest dreams ever imagine that the St.Helens technology (in an improved form, thanks to the folks in Boise) would still be on the corporate price list thirty years after intro, still shipping in 2014. This makes it by far the longest-lived product in HP’s corporate history.
Slim Volume's Star Dust Blog
Howdy pals'n'gals, Slim Volume here with a riff on something called Star Dust, which was mentioned in a recent post by a friend of mine. The narrative went something like this: he hears what he called an "atheist scientist"- I'm guessing it was probably Carl Sagan- gush about how we are all made of star dust, and responded by saying big deal- so are dog turds.
Zero-Cost Engineering: A Fruitless Enterprise
This is the atest in a series of rants from Slim Volume, recovering ex-engineer. One of my old acquaintances from my days at HP is now running his own little company here in Corvallis and contacted me recently about doing some engineering work for him on an hourly basis.
Electrical Discharge Imaging
Thesis, University of Chalifornia, Davis, 1975
Below is a scan of my Master of Science in Engineering thesis that I wrote in 1975. Back then we didn't have computers to make our graphics and everything had to be done by a draftsman. The document is below in five parts. Enjoy.