Inkless Multimaterial Printing Flexible Electronics by Directed Laser Deposition at Nano- and Microscale

Additively manufactured electronics, also known as printedelectronics,are becoming increasingly important for the anticipated Internet ofThings (IoT). This requires manufacturing technologies that allowthe integration of various pure functional materials and devices ontodifferent flexible and rigid surfaces. However, the current ink-basedtechnologies suffer from complex and expensive ink formulation, ink-associatedcontaminations (additives/solvents), and limited sources of printingmaterials. Thus, printing contamination-free and multimaterial structuresand devices is challenging. Here, a multimaterial additive nanomanufacturing(M-ANM) technique utilizing directed laser deposition at the nano-and microscale is demonstrated, allowing the printing of lateral andvertical hybrid structures and devices. This M-ANM technique involvespulsed laser ablation of solid targets placed on a target carouselinside the printer head for in situ generation of contamination-freenanoparticles, which are then guided via a carrier gas toward thenozzle and onto the surface of the substrate, where they are sinteredand printed in real-time by a second laser. The target carousel bringsa particular target in engagement with the ablation laser beam inpredetermined sequences to print multiple materials, including metals,semiconductors, and insulators, in a single process. Using this M-ANMtechnique, various multimaterial devices such as silver/zinc oxide(Ag/ZnO) photodetectors and hybrid silver/aluminum oxide (Ag/Al2O3) circuits are printed and characterized. Thequality and versatility of our M-ANM technique offer a potential manufacturingoption for emerging IoT.