Aim: To develop a polymer cutting process with GHz Burst fs lasers on intraocular lenses (IOLs) to eliminate labor-intensive, energy consuming operational steps and lower the defect rate.
Challenges: Hydrophobic polymer materials are used for IOLs offering immense biocompatibility. However, hydrophobicity brings more challenges to the cutting step of the material which is already highly sensitive to any type of machining. Currently, lenses are first hardened at -45°C to prepare for machining with a cryogenic cooling method and cut via CNC lathing. Though the target process time is achieved, defect rate remains high and cooling step introduces additional complexity and cost to the processing cycle. Although fs lasers are perfect for efficient machining of polymers, increasing their involvement in medical devices industry, there are technical and business challenges for current solutions. Polymers are more sensitive than metals in terms of heat-effect, quickly resulting in chip formation and crystallization. Therefore, pulse energy optimization is critical, limiting the flexibility in processing speed. To increase processing speed, industry works on high power fs-laser solutions with multi-beam scanning technology. However, these solutions have significantly complex laser architecture and scanning system. Above all, processing speed is a real business deal-breaker as an obstacle to industrial scalability.
Benefits: Compared to conventional CNC lathing, fs-laser solutions offer exceptional advantages like unprecedented precision bringing highest level quality, flexibility in machining structure, no tool wear and minimized maintenance, minimized/zero material and chemical waste, and minimized human contact. GHz Burst Technology proudly offers an industrially scalable solution to micromachining that enables to exploit these advantages of fs-lasers even eliminating the heat-effect, especially impacting delicate materials like polymers. It solves the processing speed problem with affordable investment, maintenance/service and operating cost. Eventually, both throughput and quality of manufacturing increases on an unprecedented level which makes this technology a candidate state-of-the-art, particularly for polymer which is widely used for high precision requiring medical devices like IOLs.
Activities & Present achievements: The experiment will optimize the haptic cutting process on IOLs. The aim is to create a proof of concept and to come up with the optimum specs for polymer materials which are scalable in all corresponding industries. This will involve the implementation of high-speed scanning and translation systems, machine learning algorithm to optimize laser parameters for high quality and high-speed polymer processing, polymer processing parameter optimization on bulk lens material and different laser-cutting experiments on lenses. An IP opportunity on polymer application is foreseen.
Current Status: Both Deliverables for the technology development phase were completed on time and passed the acceptance criteria agreed. Industrial needs and desired parameters for the lenses to be processed have been established with partners and most challenging steps for further development have been established.