Final Design

In an effort to further this bone cutting process, an advanced jig was designed and implemented to adjust to the irregularities of bone samples for testing. Specifically, new jig inserts were integrated into the current system for compatibility with several biological samples such as bone, hoof and horn (See Figures 1a-c). A stainless steel sample holder was then implemented in order to finalize samples by polishing them down to the accurate dimensions on a polishing turntable (See Figure 2d). These adjustments to the current protocol have proven to create dimensionally consistent samples for testing, while also minimizing preparation time.

Figure 1: Insert Panels for Initial Cuts & Sample Holder for Final Polishing

      (a)       (b)         (c)  (d)

Figure 2: Streamlined Bone Cutting Process

Ideally, Skyscraper was set to deal with relatively smaller samples that were more difficult to handle. Two-Face made use of its multiple contact points to more easily grip various irregular samples, usually being implemented early on in the sample preparation. Ultimately, these two insert panel designs were combined into a single insert panel, after realization that only one of Two-Face’s faces was necessary. This resulted in making the cutting process easier since there were less pieces to deal with overall. Pepe remained the same as its prototype, serving the purpose of adjust to larger samples with relatively arched shapes. All final designs consisted of an added 10-24 threaded hole at their center to provide added support for samples. Each of these components were finalized with stainless steel to prevent corrosion and maximize lifetime.

In the freeze casting process, samples tend to be very delicate before undergoing the final stage: the sintering process. In order to preserve them, the scaffolds must be maintained dry within a low vacuum state beforehand. As such, a multi-compartment desiccator was designed to be integrated within the freeze casting process, allowing for freeze casted scaffolds to be safely stored, preserving their mechanical properties (See Figure 3). These stable acrylic desiccators provide a cost-efficient and space-efficient alternative to commercial desiccators, ultimately also being less prone to damaging the scaffolds, providing an ease-of-use solution.

Figure 3: To the left is the Desiccator with Freeze Casted Samples. To the right is Three Desiccators Testing Pressure Ratings

Overall time was tremendously reduced. Using the insert panels and sample holder the lab is able to worry less about precise cuts using the diamond saw and use the sample holder in order to polish each sample down to the exact 2x2x4mm desired sample size. The final desiccator was also improved by providing a stable square structure, enough space to fit 18 samples in a desiccator at a time as well as using, see through, acrylic material to monitor samples and a pressure gage to show how much vacuum is being withheld at a time.