Multi-Material Laser Print Spray Manufacturing of Microscale Structures

By coupling the processes of laser etching and self-limiting electrospray deposition (SLED), the repeated in situ photothermal conversion of composite films can yield 3D microscale structures. This hybrid approach presents a complex multiphysics problem involving charge transport, heat transfer, and phase transformation within a localized region. An electrospray of self-limiting ink continuously supplies material as deposition sites become available through the photothermal conversion of charge non-dissipative composite to charge dissipative targets. The self-limiting nature of SLED minimizes deposition onto non-dissipative regions, providing a mechanism for localizing material growth. Iterative outward buildup from the substrate is driven by repeatedly irradiating a spot or pattern to create new deposition targets for the subsequent layers of composite film. Tuning the laser’s parameters and therefore the thermal field it induces enables precise control over the region of conversion, making on-demand printing possible. The simultaneous development of self-limiting formulations, whose deposited films can be photothermally converted into charge dissipative targets, also presents a multitude of viable materials, making this hybrid approach to additive manufacturing even more versatile.