Reviewed by Lexie CornerJan 15 2025
In the journal Applied Optics, published by the Optica Publishing Group, researchers from Tunghai University in Taiwan compared 3D printing with traditional manufacturing methods, including Computer Numerical Control (CNC) machining and reverse engineering, for producing headlight lenses.
A new study demonstrated the benefits of 3D printing for manufacturing, using a headlight lens as an example. 3D printing achieved exceptional precision and surface quality while also outperforming traditional methods in production efficiency and cost-effectiveness. The image shows the Luce Memorial Chapel in Taichung, Taiwan, viewed through one of the 3D-printed headlight lenses. Image Credit: Chia-Hung Yeh, Tunghai University
The recent study highlighted the advantages of employing 3D printing to manufacture headlight lenses. The findings show that additive manufacturing can overcome the limits of traditional manufacturing processes, allowing for increased flexibility and performance in the production of a wide range of product types.
Traditional manufacturing methods come with limitations such as high costs, long delivery times, and low yield. This study uses a headlight lens as a case study to explore the potential of 3D printing as an alternative to traditional manufacturing methods, aiming to create a faster product verification process for the industry.
Chia-Hung Yeh, Study Team Leader and Professor, Tunghai University
They discovered that 3D printing not only produced excellent precision and surface quality but also surpassed traditional methods in terms of manufacturing efficiency and cost-effectiveness.
3D-printing technology holds significant promise for producing optical components by allowing rapid prototyping of product designs, enabling designers and engineers to quickly validate the aesthetic, structural, and functional aspects of their creations. Additionally, it makes it possible to bring intricate and innovative designs to life, shortening the development cycle for new vehicle models and boosting overall market competitiveness.
Wei-Min Chen, Doctoral Student, Tunghai University
Meeting Today’s Manufacturing Needs
The optical plastics industry has evolved to focus increasingly on offering a wide range of products and addressing specific customer needs. This shift has replaced the traditional mass production model, which prioritized uniform quality, with smaller production batches and more customized solutions.
The high cost of traditional lens molds requires manufacturers to carefully evaluate the financial risks and benefits before committing to production, often leading to longer decision-making processes.
Yeh stated, “Moreover, as product designs become more complex, mold design and manufacturing processes are also becoming more intricate, which slows production speeds. To stay competitive in a rapidly changing market, manufacturing design capabilities must meet these demands quickly.”
In the current study, researchers compared 3D printing technology with reverse engineering and CNC machining, two widely used techniques for producing optical components. Using a headlight lens as a case study, the team selected appropriate materials and processes based on practical requirements and fabricated test products using each method.
Process Comparison
The researchers evaluated the production results by analyzing key aspects of the headlight lens, including light transmittance, surface profile, radius of curvature, diameter, height, and surface roughness. The 3D-printed lens exhibited a transmittance of 93 %, excellent surface roughness, and minimal curvature radius error.
This performance exceeded the 90 % transmittance of a commercially available polycarbonate lens and was comparable to the CNC-machined sample (94 %) and the two reverse-engineered lenses (91 % and 94 %).
Using a resin material costing approximately 30 USD, the team produced 14 headlight lenses in a single 8-hour print cycle. This demonstrated that 3D printing not only supports the production of one-off prototype designs but also improves operational efficiency and reduces production timelines for small-batch, high-variety manufacturing.
“3D printing offers key advantages, such as consolidating multiple components into a single structure, reducing manufacturing costs, and simplifying assembly. Overall, 3D printing in optical applications improves design flexibility, cost efficiency, and sustainability, positioning it as a transformative force in the industry as technology continues to advance,” Yeh noted.
Although this study examined different headlight lens production techniques, more investigation is required to assess lens performance in practical settings. To ensure the results can be successfully applied in real-world settings, the researchers intend to investigate particular headlamp module combinations and evaluate internal elements, including fixture temperature, operational environment, and structural design.
Journal Reference:
Yeh, C.-H. and Lin, H.-Y. (2025) Using 3D printing technology to replace the manufacturing process of a headlight lens. Applied Optics. doi.org/10.1364/AO.539164