| Description |
Porous scaffolds with tailored properties are critical to a variety of engineering and biological materials such as filters, capacitors, biomedical scaffolds, and human bone. One technique that has proven successful in the creation of porous scaffolds is freeze-casting, which has been heavily researched in the last 18 years as a successful technique for the fabrication of porous scaffolds while offering a variety of methods for altering the properties of these porous scaffolds. This method of casting uses the formation of ice crystals as the template to fabricate complex porous scaffolds. The scaffolds can be controlled intrinsically (e.g. altering the slurry constituents) and extrinsically (e.g. through forces outside of the slurry constituents) during ice crystal formation. Predominantly, freeze-cast research has been focused on intrinsic control methods. However, due to the precise application of magnetic fields, the extrinsic control method of using a magnetic field during freezing has the potential to dynamically control the structural and mechanical properties of freeze-cast scaffolds, resulting in fabricated scaffolds that have user-specified mechanical properties at user-specified locations. To do this, I employ a low-strength magnetic field with low magnetic field gradients, which are effectively uniform, created via a first-of-its-kind, custom-built tri-axial nested Helmholtz-coils based magnetic freeze-casting setup. This provides a new way to control particles during freeze-casting and allow for advanced control over the magnetic field direction to create complex porous structures. |
