Embedding functionalities in 3D printed objects is a fast-growing technology track, covering a wide range of attractive applications especially in the fields of aerospace, automative and biomedical implants etc. The in-situ monitoring of various physical parameters, particularly temperature and strain provides useful information to determine the control of complex system. Furthermore, features such as heaters allow locally acting on those systems, which is of great interest for fluidic applications. The combination of temperature sensing and controlled heating may lead to even more advanced sensing functions, such as flow measurement. We present the latest developments on compliant integration of functional nanomaterials to the inner surface of 3D printed metal pipes designed for and manufactured with Laser Powder Bed Fusion (LPBF) process. The study is focused on the process optimization of Aerosol Jet Printing (AJP) of different functional inks to integrate temperature sensors and heating functions to the pipes. AJP process parameters are optimized considering printing results on the LPBF produced substrate such as pattern resolution, uniformity, and finally on the electrical performance of the printed structures. AJP is applied to coat insulation as well as encapsulation layers on the 3D metal parts. For high resolution patterning of metallic structures, gold (Au) and silver (Ag) nanoparticles-based inks are used for development of temperature sensors and heater elements on the interior surface of metal pipes. The metallic inks are used to print contacting pads, interconnects, and the resistance temperature detectors (RTDs) targeting 1000 Ω (following Pt-1000 standards) as well as an integrated heater. Thermal cyclic response of the RTD sensor is evaluated by varying temperature between -65 °C to 85 °C in a climatic chamber, resulting in a very stable response.

Saleem is working as senior R&D Engineer at CSEM, Switzerland with research focus on additive manufacturing of functional nanomaterials and sensors development using printing technologies. He got his PhD degree from University of Trento, Italy and has more than ten years of professional experience in the field of printed electronics. Currently he is exploring the fast-emerging fields of functional 3D objects, sustainable electronics using biosourced materials and using AJP technology for various interposer projects.