There are many advantages to utilizing additive prototyping techniques for integrating electroluminescent (EL) circuitry into multi-layered electronic prototypes. Engineers and researchers can iterate and test complex designs, incorporating EL elements into various layers to create novel applications.
The versatility of this technology means innovation is top of mind in industries such as automotive — where multi-layer prototyping is enabling integration of EL panels into vehicle dashboard displays and interior ambient lighting systems. The versatility also means that the aesthetics and functionality of automotive interiors is enhanced, offering an improved experience for both driver and passenger alike.
Additive electronics also promotes the development of flexible, multi-layered devices for wearable applications — EL elements can be seamlessly integrated into clothing, accessories, medical devices, and more. The flexibility additive processes offers ensures highly customizable solutions that conform to the contours of the human body while offering unprecedented comfort and functionality.
EL ink works by harnessing electroluminescence — a light emission that occurs under an electric field — making EL ink a versatile solution for various printing applications. This research endeavors to evaluate the performance of different EL inks sourced from ACI Materials and Saralon, and simultaneously assess their suitability for multi-layer printing. The study encompasses four layers of material, including conductive silver ink, dielectric ink, blue light-emitting ink (phosphor), and conducting polymer, tested on two substrate materials — paper cardstock and polyethylene terephthalate (PET).
Direct-ink write technology — specifically the Voltera NOVA precision materials dispensing system — emerged as the preferred printing method. However, achieving smooth and even surfaces between layers emerged as a critical challenge for successful multi-layer printing. Meticulous adjustments, such as reducing probe pitch and ensuring ink mixing before printing, are imperative to achieve optimal results.
Iterative testing of each variation in materials, nozzle type, probe pitch, NOVA printing settings, and cure time and temperature resulted in a process that successfully validated multi-layer printing by achieving the desired print quality and conductivity and a fully functioning prototype. By interpreting the intricacies of multi-layer printing and assessing the performance of EL inks, this study highlights the potential of EL ink in a wide variety of printed electronics applications.
