Colloquia

Summary

The motivation of this thesis project originates abroad. Globally, just over 50% of people rely on corrective lenses to see well. Of these people, the majority lacks access to the eyeglasses they require. The lack of access to eyeglasses in the global south is identified as a problem and urgent need. Providing for such an urgent need presents a challenge.

To address this, the thesis focuses on developing a 3D printable eyeglasses frame design, eliminating the need for assembly and enabling on-demand, local production. This approach minimizes reliance on conventional manufacturing methods, which often involve shipping and other resource-intensive processes.

The research journey involved an in-depth exploration of existing eyeglasses hinges and compliant mechanisms. Affinity diagrams and morphological charts were used as tools to conceptualize a range of design possibilities. Iterations of 3D modelling, prototyping, and analysing were undertaken to develop a final hinge design. The chosen material, PA 12, emerged as the most promising after qualitative research on its properties and comparison with other materials.

The bistable hinge uses a flexible bending mechanism in combination with two semi-stiff elements that slide over each other and provide resistance once the flexible mechanism bends. When bent past a certain point, the hinge snaps into place without resistance. A 90 degree angle of rotation was chosen as it is convenient for eyeglasses design.

With the unique hinge design included in a final eyeglasses frame, it can be 3D printed as one part. A printed prototype underwent analysis and testing against the established project and industry requirements. The results were promising, showcasing compliance with set standards, though further testing is essential to determine market readiness.

This innovation takes a step towards providing access to eyeglasses in underserved regions. The ability to 3D print a working frame using a simple FDM 3D printer demonstrates the feasibility of local, resource-efficient manufacturing. The frame's design, incorporating the bistable hinge, proves that entire eyeglasses frames can be produced locally in one part, eliminating the need for assembly and expensive shipping and contributing to a sustainable eyewear industry.

In conclusion, this thesis project not only addresses a critical global need but also offers a practical solution through innovative design and technology. The developed eyeglasses frame represents a step forward in making eyeglasses more accessible, especially in regions where conventional manufacturing and distribution channels are limited.