Next-Generation Retroreflectors for Automotive

Making Car Lights Safer and Smaller
retroreflectors work by sending incoming light back in the direction it came from. In cars, the most common type uses three reflective surfaces that meet at right angles, forming a cube-corner shape. G2 Industrial Engineering’s retroreflector uses a repeating pattern of pyramid-shaped reflectors with equal-sided triangle bases. This design is easier to produce than the traditional cube-corner version.

The project included steps such as optical simulation, pattern design, creation, tooling, and copying of the structures. A micro-structured surface of 1 cm² was made, with each microstructure being up to 30 micrometers tall. The appearance of the micro-optics was also carefully considered, allowing the option to replace larger optical parts. Simulations showed that the reflector works well at light angles up to 20 degrees.

The Process Behind Microstructured Retroreflectors
The microstructured retroreflector was created using maskless grayscale laser lithography (MALA) on a photosensitive resin. Light was applied in carefully calculated amounts at specific spots on a hard surface (like a virtual mask). The quality of the surface was checked using high-resolution images from a scanning electron microscope (SEM).

For making copies, a strong nickel master was used as a reversed stamp. The tiny structures were then transferred onto flexible materials using UV light, ensuring high accuracy and consistent results. This process allows the production of precise micro-optical retroreflectors suitable for automotive use.

Improving Retroreflectors for the Automotive Industry
The study showed that the micro-structured retroreflector works well, both in computer simulations and in actual production. Some small differences in performance were found because the production process still needs optimization, but the main retroreflective function was confirmed.

“Based on these results, G2 Industrial Engineering is now moving towards large-scale production of micro-optical retroreflectors. Thanks to collaboration with PHABULOuS and partnerships with important industry suppliers, this step will ensure consistent quality and precise manufacturing,”
-Dr. Albert Krammer, Head of R&D, G2 Industrial Engineering

Our PHABULOuS Partners in this project