Search

Multimaterial 3D printing in electronics is expanding due to the ability to realize geometrically complex systems with simplified processes compared with conventional printed circuit board. Herein, the feasibility of using a copper‐based filament to realize 3D circuits with planar and vertical interconnections is presented. The resistivity of the tracks (1–3 mm wide) is studied with reference to printing parameters and orientation. Using lateral infill for 1 mm tracks offers lower resistance compared with longitudinal infill (≈75%). For wider tracks, the effect of infill orientation on resistance diminishes. The evaluation of tracks embedded in polylactic acid shows a drop in maximum current (to ≈11 mA) compared with exposed tracks (≈16 mA). There is no observed correlation between electrical performance and number of embedding layers. However, a significant correlation is observed between the tracks' resistance and the amount of time the filament remains in the heated nozzle. This in‐depth study leads to optimum resolution to realize conductive tracks of 0.67 mm thickness and the first integration of fused deposition modeling (FDM)‐printed conductive traces with small‐outline integrated circuits to open a pathway for higher‐density 3D printed circuits. Finally, the transmission of digital data by a 3D printed circuit is demonstrated. [ABSTRACT FROM AUTHOR]

Herein, the development of complex 3D intelligent structures such as robotic hands using innovative designs and multimaterial additive manufacturing technology is presented. The distal phalanges of the 3D printed hand presented herein have inherent soft capacitive touch or pressure sensors and embedded electronics. Materials such as thermoplastic polyurethane (TPU), silver paint, conductive polylactic acid composite, graphite ink, etc. are explored to develop five different variants of the sensors using a modified 3D printer, which is capable of extruding conductive ink, metal paste, and polymers. The best‐performing 3D printed soft capacitive touch sensors, formed with silver paint and soft rubber (Ecoflex 00‐30), are integrated on the distal phalanges of the 3D printed robotic hand. These sensors exhibit a stable response with sensitivity of 0.00348 kPa−1 for pressure <10 kPa and 0.00134 kPa−1 for higher pressure. To demonstrate the practical applicability, the 3D printed hand with embedded soft capacitive touch sensors is used for interacting with everyday objects. The tightly integrated sensing elements within the 3D printed structures, as presented herein, can pave the way for a new generation of truly smart material systems that can possibly change their appearance and shape autonomously. [ABSTRACT FROM AUTHOR]