Design World

  • Home
  • Technologies
    • 3D CAD
    • Electronics • electrical
    • Fastening & Joining
    • Factory automation
    • Linear Motion
    • Motion Control
    • Test & Measurement
    • Sensors
    • Fluid power
  • Learn
    • Ebooks / Tech Tips
    • Engineering Week
    • Future of Design Engineering
    • MC² Motion Control Classrooms
    • Podcasts
    • Videos
    • Webinars
  • LEAP AWARDS
  • Leadership
    • 2022 Voting
    • 2021 Winners
  • Design Guide Library
  • Resources
    • 3D Cad Models
      • PARTsolutions
      • TraceParts
    • Digital Issues
      • Design World
      • EE World
    • Women in Engineering
  • Supplier Listings

Smart Surface Enables Advanced Manipulation of Droplets

By University of British Columbia | July 25, 2017

Share

UBC-developed smart surface offers fast and reversible surface wetting properties-from superhydrophobic (water-repellant) to superhydrophilic (water-attractive) using a small voltage that could be supplied by conventional batteries. Image credit: University of British Columbia

For many years, engineers have sought to create a special kind of surface: one that can both repel and absorb liquids, and whose ability to do so — its “wetting behaviour” — can be quickly and precisely controlled. The technology would have a wide range of potential applications, from water filtration and biomedical devices to liquid optical lenses and lab-on-a-chip systems.

Such a “smart surface” has now been developed by researchers at the University of British Columbia. Inexpensive, scalable and powered by just a conventional electric battery, the copper-based surface changes from being very water-repellent (superhydrophobic) to very water-absorbent (superhydrophilic) as electric potential is applied.

“When tiny voltages are applied to the surface, water droplets that initially roll off stick to it more and more tightly,” said Ben Zahiri, the study’s co-lead author. “By changing the magnitude of the voltage and how long it is applied, we can easily control the angle that each droplet forms with the surface and how quickly this happens.”

When the electric potential is removed, the droplet retains its shape and remains pinned in place.

Other groups have modified the wetting behaviour of copper surfaces using stimuli like heat, UV radiation and X-rays. But in order to achieve this, the required temperatures are high — up to 300 degrees Celsius — and the required exposure times are long — from tens of minutes to days. This makes them impractical for a number of consumer and industrial purposes.

In contrast, the electrical stimulus used by the UBC team modifies wetting behaviour rapidly (from a few seconds to a few minutes) and reversibly, at voltages found in everyday batteries (less than 1.5 V). It does so by changing the oxidation state of the copper surface, which contains a mixture of hydrophilic CuO and hydrophobic Cu2O: as copper loses electrons, it becomes less attracted to water.

The ability to control surface wettability could be useful wherever droplets, or solid particles absorbed by droplets, need to be manipulated, including microfluidic devices and hazardous material handling systems. It also offers advanced self-cleaning capabilities by enabling the controlled roll-off of fluids.

Although the UBC team chose to investigate copper because it is cheap, abundant and one of the most commonly used metals in the world, Zahiri believes that the electrochemical manipulation of other metals, metal oxides and mixed oxides may yield similarly promising results. As for the liquid, any conductive fluid, such as blood, could be used.

“These findings could open up a new area of exploration for smart surfaces,” said UBC mechanical engineering professor Walter Mérida, who supervised the work.

This study was recently published in Advanced Materials Interfaces.


Filed Under: Materials • advanced

 

Related Articles Read More >

Self-lubricating and wear-resistant: igus bar stock for food, continuous operation and high media resistance
Minnesota Rubber and Plastics announces plans for new Innovation Center
The importance of resin selection
EXE014 - Image 1
Composite materials help place Italian race team in pole position

DESIGN GUIDE LIBRARY

“motion

Enews Sign Up

Motion Control Classroom

Design World Digital Edition

cover

Browse the most current issue of Design World and back issues in an easy to use high quality format. Clip, share and download with the leading design engineering magazine today.

EDABoard the Forum for Electronics

Top global problem solving EE forum covering Microcontrollers, DSP, Networking, Analog and Digital Design, RF, Power Electronics, PCB Routing and much more

EDABoard: Forum for electronics

Sponsored Content

  • Global supply needs drive increased manufacturing footprint development
  • How to Increase Rotational Capacity for a Retaining Ring
  • Cordis high resolution electronic proportional pressure controls
  • WAGO’s custom designed interface wiring system making industrial applications easier
  • 10 Reasons to Specify Valve Manifolds
  • Case study: How a 3D-printed tool saved thousands of hours and dollars

Design World Podcasts

May 17, 2022
Another view on additive and the aerospace industry
See More >
Engineering Exchange

The Engineering Exchange is a global educational networking community for engineers.

Connect, share, and learn today »

Design World
  • Advertising
  • About us
  • Contact
  • Manage your Design World Subscription
  • Subscribe
  • Design World Digital Network
  • Engineering White Papers
  • LEAP AWARDS

Copyright © 2022 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy | Advertising | About Us

Search Design World

  • Home
  • Technologies
    • 3D CAD
    • Electronics • electrical
    • Fastening & Joining
    • Factory automation
    • Linear Motion
    • Motion Control
    • Test & Measurement
    • Sensors
    • Fluid power
  • Learn
    • Ebooks / Tech Tips
    • Engineering Week
    • Future of Design Engineering
    • MC² Motion Control Classrooms
    • Podcasts
    • Videos
    • Webinars
  • LEAP AWARDS
  • Leadership
    • 2022 Voting
    • 2021 Winners
  • Design Guide Library
  • Resources
    • 3D Cad Models
      • PARTsolutions
      • TraceParts
    • Digital Issues
      • Design World
      • EE World
    • Women in Engineering
  • Supplier Listings