Opportunities and challenges for 3D printing of solid-state lighting systems

Low energy use and reduced maintenance have made the LED, a solid-state light (SSL) source, the preferred technology for many lighting applications. With the explosion of products in the marketplace and subsequent price erosion, manufacturers are looking for lower cost materials and manufacturing methods. 3-D printing, also known as additive manufacturing, could be a potential solution. Recently, manufacturers in the automotive, aerospace, and medical industries have embraced 3-D printing for manufacturing parts and systems. This could pave the way for the lighting industry to produce lower cost, custom lighting systems that are 3-D printed on-site to achieve on-time and on-demand manufacturing. One unique aspect of LED fixture manufacturing is that it requires thermo-mechanical, electrical, and optical components. The goal of our investigation was to understand if current 3-D printing technologies and materials can be used to manufacture functional thermo-mechanical, electrical, and optical components for SSL fixtures. We printed heat sink components and electrical traces using an FFF-type 3-D printer with different filaments. The results showed that the printed heat sinks achieved higher thermal conductivity values compared to components made with plastic materials. For electrical traces, graphene-infused PLA showed low resistivity but it is much higher than bulk copper resistivity. For optics, SLA-printed optical components showed that print resolution, print orientation, and postprocessing affect light transmission and light scatter properties. Overall, 3-D printing offers an opportunity for mass customization of SSL fixtures and changing architectural lighting practice, but several challenges in terms of process and materials still have to be overcome.