The revolutionary ideas and prototypes made possible by the advent of 3D printing, often called additive manufacturing, is revolutionizing the industrial industry. Given the characteristics of the substance, there are number of 3D printing processes. 3D printed products have significant applications in Aerospace, Automotive, Construction, Tissue Engineering, Medical, Electronics areas. Fusion Additive manufacturing includes the use of deposition modelling predominantly used for printing ABS, PLA and Composite filament-based wire-feeds to form required geometry. The designs are realized through CAD designs and sliced through Slicer software. FDM possess simplicity having smaller machine unit and provides design freedom. There are more than 150 filaments compatible with the technology including metal mixed plastic material. Printing sensors is one of the key 3D printing applications. Existing E-beam deposition of metals are fairly complex and costly. Certain process involves vacuum and pressure processing to print metals. Metals are mostly processed through fusing powder particles at very high temperature using high power laser. These are applied for macro and micro-objects. Nevertheless, FDM based process are mostly used for macro-objects. Resolution is poor for micro printing objects. Therefore, product quality needs improvement for micro printing scenario. Clogging issues during dispensing are more. Further, layering metal on a substrate is a key challenge for existing 3D metal printing processes. FDM supports layering on substrate. However, limitations exist for conductive metal layering for sensor fabrications as the current filaments are not conductive. Currently, the vertical printing resolution using plastic and plastic with metal is 50 µm. For electrochemical applications such as heavy metal ion sensors, the metal layering requires in micro or nano sizes. Hence, FDM 3D printing needs improvement in improving z-resolution or reducing the layering height for more precision.
Prakash et al. (Sat,) studied this question.