Design and implementation of an organic powder printer

Abstract

Organic powders are polymers with organic origin in a powdered form. They are biocompatible, biodegradable, and possess positive biological attributes, and can form constructs with high mechanical properties due to their powder form. However, there are various constraints that limit organic powders to be solely used with current 3D printers. Many organic powders cannot be fused by heat and light exposure and not easy to dissolve by the printing ink. Moreover, binding solutions for silk and other organic powders are mostly acidic in nature which cause damage to current 3D powder printers as they use neutral or slight low pH inks. This work aims to address this problem by developing a 3D printer that enables the printing of an organic powder, silk. This paper presents the design and implementation of the first prototype of a novel organic powder printer. The printer incorporates a novel compression mechanism that enables the compression of the powder during the printing process. It also includes a non-corrosive binder supply system consisting of silicone peroxide tubing, a custom-built peristaltic pump, and a nozzle built from a 33-gauge needle. The powder management system consists of a powder canister apparatus, depositing mechanism, and a powder bed designed to be compatible with low flowability powders, such as silk powder. The implementation of each component and the whole printer is presented. Evaluating the functionality of the organic powder printer found that several silk powder scaffolds were able to be printed with a varying magnitude of control over architecture. Future work is required to further advance the printable constructs up to a standard found in commercial 3D printers. This work demonstrated that a 3D printer system can be developed to fabricate constructs solely out of an organic powder. The paper highlights the limitations of the current design and suggests future improvements.