Additive manufacturing of IoT housings with integrated electronics

Abstract

Additive manufacturing (AM) is an established fabrication method for diverse applications. Due to the versatile manufacturing possibilities, AM provides totally new approaches in designing objects. An emphasis in the field of research was set to the development of unique materials for AM. Among them, conductive filaments were examined for applications in printed electronics. The combination of new materials and the innovative design approach offered by AM generates a comprehensive field of applications. Promising applications can be found on the “Internet of Things (IoT)” sector. The development of connected products includes physical and electronic components. Traditionally, the fabrication process of these products is linear, thus, the design and the fabrication of the physical components is separated from the electronic part. To overcome this separation, an AM approach can be applied in the fabrication of IoT devices. This additive multi-material fabrication approach enables the fabrication of mechanical and electric components in one fabrication process. To prove this fabrication approach, antennas for IoT devices consisting of a supportive element and a antenna element for signal transmission were designed. The antennas were fabricated by material extrusion combining non-conductive and conductive filaments. Two different antennas (patch and arc antenna) were designed focusing on one specific frequencies range: 868 MHz (LoRa). To compare the AM antenna, reference antennas have been fabricated by etching. Antennas were characterized by simulation and measuring the return loss of the fabricated specimen. Finally, the transmission of a payload was tested in a real-world scenario. The tested antennas were able to transmit a payload, however, the return loss differed between the different designs and fabrication approaches. Nevertheless, the additive multi-material fabrication process enables an integrated production approach which led to functional devices. In this sense, electronics and physical components are merged into a truly smart product. Based on the findings, further applications of the hybrid approach will be investigated e.g., signal traces, passive electrical components to further strengthen the extensive application possibilities of additive manufacturing.Graphical abstract