Pneumatic system design for direct write 3D printing

Direct write 3D printing methods are interesting due to the diverse palette of materials available for the process. In this work, a pneumatic system for direct write printing is built using off-the-shelf hardware and synchronized with an open-source firmware for motion control. The time to steady-state pressure of the system is found to be ~150 ms for the range of pressures tested; this delay can lead to defects on the start of a path. Proof of concept is established by printing with a high viscosity, room temperature curing silicone using a 410 µm nozzle and 300 µm layer height. Test prints show a high degree of dimensional accuracy and consistent layer height over 10s of layers.