Opalux has developed a range of innovative, optically variable security devices to combat counterfeiting and improve the authentication of banknotes, passports and other high-value items.
Opalux’s tunable photonic crystals are at the heart of all its security features. Like the opal, which is a naturally occurring photonic crystal, Opalux’s security features have bright, unique chromatic appearances. Also like the opal, Opalux’s security features have a precise nanostructure which makes them optically variable: their appearance changes when viewed at different angles and under different lighting conditions. For example, transitions between bright reds, yellows, greens and blues, or even ultraviolet and infrared, are possible as lighting and viewing angles change.
Additionally, and unlike natural photonic crystals, Opalux’s photonic crystals are tunable, meaning that their appearance changes in response to a range of stimuli, including laser energy, pressure, electric current and chemicals. This tuning provides further layers of security and customizability. The result is security features that engage users and provide straightforward authentication solutions.
The nanostructure of each of Opalux’s security features has been carefully designed by Opalux’s expert scientists and engineers. Customization of this nanostructure allows Opalux to create variations in appearance and ensure compatibility with a wide variety of processing techniques.
Opalux’s latest development is OpalPrint Polycarbonate, a personalized high security feature that combines the document holder’s portrait with a bright, attractive, optically variable, colour-shift image. This makes the document difficult to counterfeit and fraudulently alter, easy to verify and attractive to view.
Compatible with standard polycarbonate lamination equipment, the integrated polycarbonate document structure incorporating the embedded OpalPrint feature ensures tamper-resistance and document longevity. OpalPrint is personalized using security industry-standard laser personalization techniques, making it suitable for centralised and decentralised issuance, providing flexibility, speed, accuracy and ease of integration.
ElastInk is Opalux’s interactive security feature. In addition to its inherent optical variability, ElastInk changes its appearance in response to the application of finger pressure. Elastink can be produced in a wide variety of form factors, including as a security thread for paper banknotes. This latter variant meets circulation hazard requirements for paper banknotes.
Depending on customer and security requirements, Elastink’s appearance change can be either reversible or irreversible. For example, when used as a security thread in a banknote, a reversible variant is employed. However, for other applications such as tamper evidence, irreversible variants and variants that reverse in response to specific stimuli (like heat) may be employed.
ElastInk is available in a range of initial colours, including red, yellow, green and blue, and a variety of pressure thresholds. Several variants of ElastInk are reserved for high security documents.
Photonic Ink is an RFID-activated security feature. Photonic Ink changes its appearance in response to the presence of an RFID field and is optically variable.
Photonic Ink operates at low voltages and current and can maintain static images with negligible energy. In addition to RFID fields, it responds to electrical charge and can be deployed on rigid and flexible surfaces.
The human nose works by using a large array of olfactory neurons, each responsive to a different stimuli. By working in combination with each other, this array of olfactory neurons detects a wide range of substances, quickly, reliably and inexpensively.
Inspired by the human nose, Opalux’s Photonic Nose uses an array of photonic crystal sensing units. These sensing units, in conjunction with a digital camera and image analysis software, permit the detection of a wide range of substances.
Simpler versions, which change appearance in response to simple stimuli like water vapour, are also possible.