DEVELOPMENT AND IMPLEMENTATION OF 5 DEGREE OF FREEDOM BIOPRINTING MOTION STAGE, CONTROL SOFTWARE AND TOOLPATH GENERATION ALGORITHMS.
Open Access
- Author:
- Povilianskas, Adomas
- Area of Honors:
- Engineering Science
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Dr. Ibrahim Tarik Ozbolat, Thesis Supervisor
Dr. Gary L Gray, Thesis Honors Advisor - Keywords:
- bioprinting
5dof
motion stage
3D printing - Abstract:
- Bioprinting complex scaffolds and biostructs using conventional 3-axis bioprinting platforms is a challenging and sometimes even an impossible task. This paper discusses the design, fabrication, building, programing, and testing of a functional prototype that demonstrates an ability to bioprint complex scaffold designs using a 5 axis, 5 degrees of freedom (DOF) bioprinting platform. The ability to control the approach angle of the tool with additional 2 degrees of freedom will allow bioprinting of scaffolds along angled, uneven and concave surfaces such as the cranial of human’s skull. While conventional 3 DOF bioprinters can follow the topology of a curved surface the tooltip approach angle is always fixed normal to the building platform. Maintaining the tooltip normal to the surface of the subject is important because the shape of the deposited bioink strands needs to be uniform throughout the scaffold in order to maintain the porosity and shape of the scaffold. This can be achieved only along the X-Y plane while using a conventional 3 DOF bioprinter, therefore, at least two additional degrees of freedom need to be implemented in order to produce complicated 3D geometries as shown in figure A. Another major challenge while bioprinting with 5 DOF devices is bioprinter control and generation of toolpaths. Conventional bioprinters utilize open-source model slicing software developed for 3D printers and generate the tool paths in 2D layers along X-Y plane. Generating 3D toolpaths is very challenging and only closed-source, feature limited proprietary software solutions are available. Therefore, the bioprinter control and 2D/3D toolpath generation software were developed which can control a variety of different types of devices such as extrusion-based, droplet-based and aspiration-assisted bioprinters. The ability to control different types of bioprinters and generate the toolpath using a single software interface reduces the preparation and calibration time when transferring the subject between different bioprinters which are not interconnected by uniform software interface.Several design alternatives of the motion stage and end effector were evaluated and the 5DOF bioprinter design was chosen, because it scored the highest in terms of portability, build volume/footprint ratio and cost on the Design Alternative Matrix. This project was completed in accordance with the action plan (see Appendix A), that has 4 primary tracks which include design, fabrication, software development and writing. This project is under active development.