Air‐Pressure‐Assisted Pen‐Nib Printing for 3D Printed Electronics

Abstract

3D printed electronics employing direct‐ink‐writing methods are promising alternative manufacturing technologies for realizing structural electronics. The emerging demand for accessible, cost‐effective, and rapid writing calls for novel approaches to print functional components onto nonflat and 3D architectures. This study presents a novel air‐pressure‐assisted pen‐nib printing approach producing electrical and functional components with various material inks on flat and 3D surfaces. Based on the inks’ rheological properties, the ejected ink's quantity through the nib is manipulated via air pressure; thus, the printed line width is controlled. This strategy also achieves the viscosity range extension of printable inks by enabling printing inks that cannot be used in general pen‐based printing. Three functional inks with different rheological properties—Ag catalyst ink for Cu electroless deposition, Ag‐PEDOT:PSS ink, and thermochromic pigment inks are designed. Several electrical and functional components, such as highly conductive Cu interconnects, Cu spiral coils for wireless power transfer receivers, flexible heaters, and matrix data codes based on temperature‐responsive color transitions are demonstrated. Furthermore, parallel printing with a multi‐nib print‐head is demonstrated for improving the printing speed and manufacturing scalability. The authors believe that this novel approach is promising as a manufacturing technique for realizing 3D printed electronics.

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

“…As an alternative to the Pd seeding, some studies employed conductive pastes (e.g., silver (Ag) paste) followed by electroless deposition (ED) to create structural polymer electronics with high electrical conductivity (42.6 × 10 6 S m −1 ). 19 Even though Ag is an excellent seed material (catalyst) to activate the ED process, 20 it remains necessary to replace the high cost of Ag-based compounds with a more cost-effective and abundant metal catalyst. Taken all together, these above-mentioned limitations of current manufacturing approaches impede the rapid and large-area metallization of AM-based polymer prototypes, and thus there is a critical need for high-throughput surface metallization methods for 3D-printed polymers made of cost-effective offthe-shelf polymer filaments.…”

“…Besides, laser-induced metallization was also proposed to achieve high-resolution conductive patterns on the 3D-printed polymers from Pd-embedded polymers. , Nevertheless, Pd is a rare and expensive catalyst material, which can limit the cost-effective and large-scale utilization of these techniques. As an alternative to the Pd seeding, some studies employed conductive pastes (e.g., silver (Ag) paste) followed by electroless deposition (ED) to create structural polymer electronics with high electrical conductivity (42.6 × 10 6 S m –1 ) . Even though Ag is an excellent seed material (catalyst) to activate the ED process, it remains necessary to replace the high cost of Ag-based compounds with a more cost-effective and abundant metal catalyst.…”

Detailed Characterization of a Fully Additive Covalent Bonded PCB Manufacturing Process (SBU-CBM Method)

“…In recent applications, primarily two additive material deposition techniques are used to pattern metallic traces on flexible substrates, i.e., parallel and sequential methods. Direct-write material deposition technology falls under sequential methods, which have the capabilities to create patterns with minimum feature sizes and resolution [14][15][16][17]. As most of the electronics production methods have started using polymers, the metallization process is thus facing challenges such as higher temperature deposition, uniformity, step coverage, throughput, etc.…”