Groovy butterfly wings for better bank notes

July 17, 1998

The next generation of bank notes could make use of a security feature based on a novel characteristic of butterfly wings - a surface covered by a microscopic set of grooves that are finer than the wavelength of light.

The array of ridges and ribs on the butterfly wing allows the surface to generate colours without pigments. Swiss physicist Michael Gale has been developing ways of manufacturing this array for use on credit card and bank notes.

Speaking at a physics conference at Bath University he said the effect is similar to holograms used on credit cards but with several advantages. "It is more difficult to forge, and it shows well-defined colour changes if you rock the card from side to side or rotate it. It also works well in poor light," he said.

You've reached your article limit.

Register to continue

Registration is free and only takes a moment. Once registered you can read a total of 3 articles each month, plus:

  • Sign up for the editor's highlights
  • Receive World University Rankings news first
  • Get job alerts, shortlist jobs and save job searches
  • Participate in reader discussions and post comments
Register

Have your say

Log in or register to post comments

Most Commented

James Fryer illustration (27 July 2017)

It is not Luddism to be cautious about destroying an academic publishing industry that has served us well, says Marilyn Deegan

Jeffrey Beall, associate professor and librarian at the University of Colorado Denver

Creator of controversial predatory journals blacklist says some peers are failing to warn of dangers of disreputable publishers

Hand squeezing stress ball
Working 55 hours per week, the loss of research periods, slashed pensions, increased bureaucracy, tiny budgets and declining standards have finally forced Michael Edwards out
Kayaker and jet skiiers

Nazima Kadir’s social circle reveals a range of alternative careers for would-be scholars, and often with better rewards than academia

hole in ground

‘Drastic action’ required to fix multibillion-pound shortfall in Universities Superannuation Scheme, expert warns