IrisGuardSm-150x150As a world leader in iris recognition technology, IrisGuard, based in Milton Keynes, Buckinghamshire, is driving the development of their latest security device EyePay® by utilizing working Stereolithography (SLA) prototypes, produced in a clear, ABS-like material which are then painted; the prototype parts are being produced for IrisGuard by Graphite Additive Manufacturing.

Background
IrisGuard technology is based on the science that every human eye is different, providing a unique identifier for each individual in the world, for accurate, fast and secure biometric personal identification solutions. The range of imager products from IrisGuard and their latest development EyePay®, the world first iris camera system designed for use in retail shops to enable customers to pay for their shopping using their eye only, all work on the same principle that they scan the iris and immediately compare it with every record in the database to give accurate and reliable authentication.

The database is generated by taking focused, pristine black and white images of a person’s iris and mathematical algorithms convert the image into a unique digital code which is stored and then used for rapid matching whenever the iris is scanned.

EyePay® Form and Fit Prototyping
As part of their product development cycle, IrisGuard engineers needed to test market their latest innovative product and approached Graphite Additive Manufacturing, based in Aylesbury, to manufacture working functional prototypes for their trials. The assembled working prototypes, each made up of 20 individual parts, were used as working models in a variety of different ways through the development phase of the EyePay® product.

Initially the prototypes were used for visual and aesthetic checks, and then for internal testing by IrisGuard engineers to check for accuracy in the fitting of key components such as the optic units and the internal electronics, which helped to drive the evolution of the product design through to the final approved stage. Later on in the development cycle, the working models facilitated in explaining the new technology to both the internal sales and marketing teams as well as potential customers to give them a realistic impression of how the final product would look and perform compared with just seeing a block visual model.

These semi-real-world models also provided a great level of confidence to the engineers during design iterations ensuring accuracy and fit were optimised and most importantly provided design verification and approval of the final geometry for the production metal tooling.

Stereolithography Working Models
Material selection was very important to the project to ensure the prototypes produced could withstand the fitting together of the multiple snap-fit mounts and parts, the positioning of the internal electronics within the casings as well as the general handling and use during the operational trials. In addition IrisGuard also wanted to paint and sometimes chrome plate the models to represent the appearance of the final components once manufactured, as closely as possible so the material selected also needed to accommodate this key customer requirement. Kevin Lambourne, Managing Director at Graphite Additive Manufacturing, led the project to produce the working prototypes and after a thorough analysis of the application requirements recommended the use of Graphite’s Clear ABS-like Stereolithography material for the manufacture of the form, fit and functional models. This specialist photopolymer was ideal for the application because it not only allowed the production of highly accurate models to check the fit of each key component in the unit but also provided the material properties of a functional part, allowing the models to be screwed and tapped during assembly and painted and chrome plated when used for field trials. For this project, three full working prototype models were built through different stages of the product improvement design phase with an additional two working models being built once the final modifications had been made, which were used for the field trials.

“We have worked on multiple projects with Graphite and have always been extremely pleased with the accuracy and the quality of the prototype parts produced as well as the speed in which they are delivered to us,” commented Andy Holland, VP Research & Development at IrisGuard. “The use of working prototypes both internally and for field trials is a key driver in our product development cycle and always provides us with a much greater level of confidence as we move forward in launching these new innovative products into the market place.”

Conclusion
Production tooling is extremely expensive and having to modify any production tool through welding and regrinding is not a favourable decision for any company. The use of functional working prototypes has helped IrisGuard to speed the development and introduction of this innovative product to market by allowing the initial design in CAD to be improved visually and mechanically by working directly with an accurate 3-dimensional model. The designer could ensure the new product was visually correct, optimise the geometries of the design for form and fit as well as ensure the final mechanical design could be successfully manufactured in production without the need for changes to complex metal tools.