Johnson Matthey Inc.

Wen-Kai Hsiao

Harry J Coles

Damian Gardiner

Stephen Morris

Timothy Wilkinson

Ian Hutchings

Philip Hands

A method of manufacturing a security feature for identifying objects or documents of value. The method may include the steps of encoding information in a pattern; and ink jet printing a chiral nematic liquid crystal material from a reservoir using a print head on to a substrate in the pattern. Thus, the method forms a patterned array of chiral nematic liquid crystal material deposits. The print head, or the reservoir, or both, may be heated to a temperature above the clearing point of the chiral nematic liquid crystal material. The chiral axes of the chiral nematic liquid crystal material deposits may be aligned substantially perpendicular to the substrate such that a predetermined portion of the electromagnetic spectrum is selectively reflected over other regions of the electromagnetic spectrum by the chiral nematic liquid crystal material deposits.

Printing of liquid crystal droplet laser resonators on a wet polymer solution and product made therewith

A photonic device is manufactured by: (i) providing (e.g. by inkjet printing) an aliquot of a liquid crystal (LC) material; and (ii) depositing the aliquot onto the surface of a flowable material layer to form a liquid crystal deposit, the flowable material and the LC material being substantially immiscible. The liquid crystal deposit adopts a deformed shape relative to the shape of the aliquot due to interaction with the flowable material layer. This promotes alignment of the LC material. Incorporation of a laser dye allows the photonic device to function as a laser, which can be operated above or below threshold depending on the circumstances. The photonic device can also be used as a passive device based on the photonic bandgap of the aligned LC material.

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Cambridge, United Kingdom

Wen-Kai Hsiao