Selective Surface Metallization of 3D-Printed Polymers by Cold-Spray-Assisted Electroless Deposition

Abstract

Selective surface metallization of insulating polymers is of particular interest in smart films, energy harvesting, and sensing applications. However, traditional polymer metallization techniques face challenges due to the need for environmentally hazardous pretreatment (e.g., strong acid etching) and costintensive palladium seeding processes, thereby limiting the largescale deployment of metallized polymers. With the advent of rapid prototyping, metallization on additively manufactured polymers drew attention in a variety of technological applications, as it enables the fabrication of low-cost electronic devices. In the current work, we deploy and evaluate a hybrid additive metallization route that can enable the fabrication of functional selective metallization on 3D-printed polymers in a rapid and eco-friendly methodology with improved electrical conductivity. The metallization route sequentially comprises (1) material extrusion 3D printing, (2) cold spray metallization, and (3) electroless deposition. The resulting metal (copper) layers on the polymer surfaces are characterized in terms of the microstructure, surface chemistry, wettability, and electrical conductivity. Notably, selective metallization with promising electrical conductivity (i.e., 6.47 × 10 6 S m −1 for ABS and 5.27 × 10 6 S m −1 for PLA parts) is achieved on both linear and curvilinear polymer surfaces. Moreover, strong adhesion between the metallized layer and the 3Dprinted structures was confirmed by adhesion tests. Detailed evaluation of the proposed hybrid metallization route unlocks great potential to advance the field of conductive surface metallization on 3D-printed polymers.

Fully Additively Manufactured Counter Electrodes for Dye-Sensitized Solar Cells

“…Under these 3D printing configurations, the PLA substrates with dimensions of 25 mm length, 20 mm width, and 3 mm thickness were fabricated. That said, 3D printing of the substrate holds great potential for producing polymer CEs for DSSCs, owing to the critical advantages of 3D printing, including design flexibility, rapid prototyping, reduced material waste, ease of iteration and customization, and cost-effectiveness [14].…”

“…In detail, firstly, polylactic acid (PLA) substrate is accurately produced through material extrusion-based 3D printing. Herein, the 3D printing of polymer substrates offers significant advantages, including rapid prototyping of customized parts, near-net-shape design of intricate components, reduced material waste, and on-demand production [14,15]. Next, the substrate surface undergoes conductive metallization via CS particle deposition, which facilitates the solid-state direct writing of micron-scale metal particles on the polymer surface as a thinfilm due to its unique features, including low-process temperature, high adhesion strength, corrosion resistance, and durability [16,17].…”

Advancements in Electrodeposition for Precise Manufacturing and Sustainability

“…82 It is also possible to selectively ELES plate the surface of polymeric parts by cold spraying the activator. 83 In the framework of selective ELES plating on AM pieces, one of the most promising approaches is the use of self-activating materials. These materials enclose, directly during the AM step, the activator for ELES, either as precursor or as metal particles.…”