Recently, Optomec was awarded a NASA SBIR contract for the further development of an Adaptive Laser Sintering System (ALSS). The success of this endeavor will enable electronic circuitry to be printed onto a wider variety of temperature sensitive substrates, expanding its use for production applications.The fully automated system will also enable printed circuitry to be repaired or manufactured with minimal human intervention, paving the way for its use in long duration NASA space missions.
Dr. Feng’s presentation will explain how Optomec has been working with Harding University to develop a robust, intuitive Adaptive Laser Sintering System (ALSS). Successful development of laser assisted drying and sintering of 3D printed electronics will greatly reduce the production time for 3D printed electronics devices and substantially reduce the need for human intervention.
With printed electronics, the circuits are printed on thermoplastic and thermoset polymer materials that provide the desired structural and insulating properties of multifunctional 3D devices. The conductive lines are printed by additive manufacturing processes typically in the form of liquid metal nanoparticle (NP) inks.
In order to meet the required circuit functionality, the printed ink material must be transformed to a solid metal path (called metallization) by sintering at elevated temperature. Dr. Feng will discuss how metal nanoparticles are widely used in conductive inks because they enable relatively low sintering temperature (some as low as 100°C), compatible for fabricating circuits on common plastic substrates.
Dr. Feng will describe Optomec’s laser-based process that transmits energy locally for sintering the printed metal ink with a small heat-affected zone in milliseconds when scanning over the printed feature. With very short heating time and a small heat-affected zone, the localized peak sintering temperature can be substantially higher than that of damage threshold for the underlying substrate, to yield effective metallization with desirable electrical resistivity. Applications toward thermocouples, strain gauges, and 3D interconnect on flexible film and 3D mechanical structures will be demonstrated.