Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

Intelligent Machines

Tiny Bubbles

Desktop printing was revolutionized by a misplaced soldering iron.

Inkjet printers that commit electronic words and images to paper inhabit most computer-equipped homes and offices. Costing as little as $100, the machines form a multibillion-dollar industry. But the road to that market required some twists and turns, including a serendipitous lab accident.

In the late 1970s, Canon was one of several companies pursuing inkjet technology to create text and pictures at resolutions much higher than dot-matrix printers could achieve. Like its competitors, the Canon team was trying to use pressure to push tiny, controlled amounts of ink out of nozzles. Their initial plan was to fabricate the nozzles out of a piezoelectric material; electronic signal pulses would deform the nozzle so that it would first suck ink into a chamber, then force it out. But that approach was abandoned in 1977 shortly after a carelessly placed soldering iron touched the tip of an ink-filled syringe-and changed the direction of their research. The hot tool boiled the ink, and as the bubbles expanded, they forced the ink out of the syringe. Canon’s Ichiro Endo realized that heat might lead to a better approach. (A Hewlett-Packard team independently hit on the same idea in 1978.)

Canon demonstrated the prototype “bubble jet” printer in 1981; a commercial version debuted in 1985. Other companies, including Lexmark and Xerox, adapted and enhanced the technology. Epson went on to develop inkjet printers using piezoelectric technology. In today’s thermal inkjet printers, tiny heating elements reach temperatures of 500 C, vaporizing minute amounts of ink for a few millionths of a second. As bubbles form and expand, nozzles like those shown above eject droplets of ink as small as four trillionths of a liter. Print heads containing 300 to 600 such nozzles squirt thousands of drops per second as they scan back and forth across a sheet of paper.

This story is part of our January/February 2001 Issue
See the rest of the issue
Subscribe

Researchers are now using inkjet printers to spray more than just ink. Last May, Sandia National Laboratories used an HP printer to deposit self-assembling nanostructures that could one day form ready-to-use sensor arrays or photonic circuits. Even PC circuits might be printed using piezoelectric inkjets if research at MIT’s Media Lab pans out (see “Print Your Next PC,” TR November/December 2000).

Become an MIT Technology Review Insider for in-depth analysis and unparalleled perspective.

Subscribe today

Uh oh–you've read all of your free articles for this month.

Insider Premium
$179.95/yr US PRICE

More from Intelligent Machines

Artificial intelligence and robots are transforming how we work and live.

Want more award-winning journalism? Subscribe to Insider Online Only.
  • Insider Online Only {! insider.prices.online !}*

    {! insider.display.menuOptionsLabel !}

    Unlimited online access including articles and video, plus The Download with the top tech stories delivered daily to your inbox.

    See details+

    What's Included

    Unlimited 24/7 access to MIT Technology Review’s website

    The Download: our daily newsletter of what's important in technology and innovation

/
You've read all of your free articles this month. This is your last free article this month. You've read of free articles this month. or  for unlimited online access.