Context:
With the widespread adoption of 3D printing and especially Fused Filament Fabrication techniques, the need for the development of robust monitoring methods to ensure print consistency and product quality has arisen.
Currently most (consumer grade) FFF 3D-printers do not feature movement and or process sensing abilities, operating by purely following instructions without verification of their correct execution. Monitoring of the printer through its motion/extrusion system, printhead/bed/filament temperatures, printhead acceleration and vision algorithms have been proposed as possible solutions with varying success.
Our group is currently developing a methodology that can directly measure the properties of the produced part as it is being printed. Making use of Electrical Impedance Tomography (EIT) in combination with conductively doped polymers, an image of the produced part and inter-layer adhesion can be derived.
Project description:
In previous work, a setup was developed to be able to determine the properties of the melt pool in the extruder hot end. The system can determine extrusion pressure, filament and melt pool impedance, and the temperatures at various places in the system, monitoring all observable parameters in the extrusion process.
The aim of this assignment will be to develop a competent model for nozzle material flow based on hot end measurements such as temperature, feed rate and previous history. This model will then be applied in a correlation study of melt impedance and extrusion rate with respect to material flow from the nozzle. The final goal being a model capable of predicting the effects of extrusion speed excursions and melt pool temperature on melt pool impedance and on the material flow rate.
Student background:
We are looking for an MSc student from EE, ME, AP or robotics, e.g. with a BSc in similar programmes or Advanced Technology. Preferably, students have previous experience with (customized) FFF 3D printers and material science. Please submit your CV when interested in this assignment.
Contact: h.r.jonkers@utwente.nl