Additive Nanomanufacturing of Multifunctional and Multimaterial Devices

Abstract

There is always great interest in finding new advanced manufacturing techniques to pave the way for the realization of future flexible and wearable electronics. Direct printing of functional materials, structures, and devices on various platforms, such as flexible to rigid substrates, is of interest for applications ranging from electronics to energy and sensing to biomedical devices. Current additive manufacturing (AM) at microscale processes is either limited by the available sources of functional materials or requires precisely designed inks. In addition, surfactants/additives in inks add further printing complexity and contamination issues to the process. Here, we report a novel laser-based additive nanomanufacturing (ANM) approach capable of in-situ and on-demand generations of nanoparticles that can serve as nanoscale building blocks for real-time sintering and printing of various multifunctional materials and patterns at atmospheric pressure and temperature. We show the ability to print different materials, including titanium dioxide (TiO2), barium titanate (BTO), and indium tin oxide (ITO), on various rigid and flexible platforms such as silicon dioxide (SiO2), paper, polydimethylsiloxane (PDMS), and polyethylene terephthalate (PET) substrates. This nonequilibrium process involves a pulsed laser to ablate targets and in-situ formation of pure amorphous nanoparticles at atmospheric pressure and temperature. These amorphous nanoparticles are then guided through a nozzle via an inert carrier gas onto the surface of the substrate, where they are sintered/crystallized in real time. We further show the process-structure relationship of the printed materials from nano to microscale. We demonstrated the dry printing and additive nanomanufacturing of flexible hybrid electronics and sensors on flexible polyimide and PET substrates. The electrical and mechanical characterization of the printed lines are studied, different flexible hybrid electronics designs are printed, and the performance of the devices is tested. 3 In order to print lateral and vertical hybrid structures and devices, we adjusted and used the ANM printer’s multimaterial additive nanomanufacturing (M-ANM) function. Numerous multimaterial devices were produced and tested, including hybrid silver/aluminum oxide (Ag/Al2O3) circuits and silver/zinc oxide (Ag/ZnO) photodetectors. Since copper (Cu) is the 25th most prevalent metal in the world, it is less expensive than silver (Ag). Because of its enormous potential, printing Cu has gained increased attention. The ANM method allowed us to achieve the resistivity of 12 μΩ.cm. A 5-month measurement of the printed Cu's resistance revealed very little fluctuation, indicating the long-term durability of the printed Cu. The ASTM adhesion test's 5B classification verified the good adhesion on the substrates. Among the plethora of semiconductor materials, Zinc Oxide (ZnO) emerges as a compelling candidate for Schottky diode fabrication, propelled by its unique properties and promising prospects in electronic devices. ZnO, with its wide bandgap, high electron mobility, and intrinsic stability, presents an intriguing avenue for enhancing device performance and functionality. Its compatibility with various deposition techniques further accentuates its appeal, enabling precise control over device architecture and characteristics. The LASED process used in this study is a dry multi-material printing technology that enables the on-demand generation of nanoparticles from solid sputtering targets and subsequently laser-sinters them in real time, creating 2D patterns. The Schottky diode fabrication strategy, Raman, XRD and current-voltage (I-V) analysis are presented.