Making Waves for the First Time

WaveFront Technology – a California-based supplier of nano and micro-structured tools, coatings and films for the security, lighting, aerospace, and display markets – used the Banknote & Currency Conference in February as an opportunity to debut its new new portfolio of security features for currency and other security applications.

Perhaps best known amongst those in the optical features sector in the past for its development of hologram and replication technology, and for its Fresnel lenses, Wavefront has built on its grayscale lithography, e-beam origination, diamond turning and wide web roll to roll UV casting lines capable to engineer the new features.

They comprise optical micro-structures that display a range of different effects according to the viewing angle, including sharp and distinctive image switches and 3D depth, making them suited for high security applications. Judging by the crowds around their booth in Washington DC, the market certainly seemed to think so.

Liquid Silver (LS) is a grayscale optical feature with 3D depth, while Liquid Silver Flip (LSF) also features a binary image flip. According to Chris Rich, co-founder and CEO of Wavefront, the LS development was based on a simply question from a customer – what’s next after the Fresnel lens pattern that Wavefront is known for embossing/packaging film market?

‘To us it was obvious, he said. ‘We wanted to maintain the same basic effects as the Fresnel Lens, but we needed to develop a freeform process that could create the liquid silver morphing images like the evil villain in the hit movie ‘Terminator 2’. With this technology we can create distinct images that can be independently viewed at different angles.’ In addition to LS and LSF, the company has also developed And Hyperfocal Lens Arrays (HL). This feature comprises a 1D lens array over a patterned microstructure that provides a high contrast image with depth that can flip, shift and even animate.

Current samples have achromatic backgrounds but can be produced in coloured and colour shift options as well. All are available in films from 20-75 microns. LS and LSF are also available in hot and cold transfer foils. Complementary processes include demetallisation and laser marking.

The company is now looking to grow and find a strategic partner with a proven production capability that can facilitate the entry of the new features into the security marketplace.

It also has more developments in the pipeline specifically targeting ‘see thru’ effects, with optical efficiency rivalling volume holograms but without the downside of their production cost that have limited their adoption into the market.