Fun with Fluids

Ink-jet printers, flat-panel displays and biochips all require the precise placement of microscopic amounts of fluids, but getting fluids to go where you want takes a lot more than just asking nicely. Researchers at Philips Research Laboratories in Eindhoven, the Netherlands, have come up with a promising approach. Their “electrocapillary” system, which uses no moving parts, shuttles fluid quickly through tubes as narrow as 350 micrometers wide-roughly three times the width of a human hair.

The tubes are actually filled with two fluids, which repel each other: one fluid is electrically conductive while the other is insulating. The wall of the tube also repels the fluids, but it’s lined with electrodes. When the electrodes are charged, the walls exert less force on the conducting fluid, which is squeezed up the tube by the greater force exerted by the insulating fluid. The fluid moves at several centimeters per second, which is about a hundred times faster than the speeds other electrical techniques deliver. A Philips group led by Menno Prins has demonstrated a network of thousands of such electrocapillaries, which they say could have applications in optical switching.

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

Insider Premium
$179.95/yr US PRICE

Want more award-winning journalism? Subscribe to Insider Basic.
  • Insider Basic {! insider.prices.basic !}*

    {! insider.display.menuOptionsLabel !}

    Six issues of our award winning magazine and daily delivery of The Download, our newsletter of what’s important in technology and innovation.

    See details+

    What's Included

    Bimonthly magazine delivery and 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.