Mouse Hip Gel Encapsulation

This early design featured a claw to hold a syringe that would pierce the tissue sample and hold it in place inside the mold which had detachable caps for easy mold removal. The setup involved a glass plate underneath and would be placed on a UV light source. I modified the claw stand to be detachable since the printed models broke quite easily during setup.

The syringe idea was not workable since I found that the cartilage could not be pierced with a needle and nondamaging options would be best. A pipette tip was not quite useful and the mold leaked during initial testing, but I thought this idea could have some merit, so I tried to leak-proof the mold pieces using laser-cut gaskets, acrylic, and clamps.

I tried to circumvent the pipette issue by redesigning the top portion with threads to hold a threaded rod with a point to keep the tissue in place. I ran into issues with size limitations and the ability for 3D printers to print threads, so I had to scale up the design.

Overall, there were a number of issues with this design, the largest of which was the inability for the gel to crosslink when exposed to air, so I ultimately decided to start from scratch.

At this point, I went back to the basics I learned from the Tissue Carrier project and decided to focus on keeping the hydrogel solution away from air during the UV crosslinking process, which meant using a gasket and clamp setup again. Clamping glass to the gasket alone caused the glass to crack, so I had to use 1/4 in acrylic on the top and bottom of the sandwich, and switched to C-clamps since the stack was too wide for the clips I had previously used. I also had to laser-cut a stand for the setup so it could stay level during UV.

I experimented with needles to see if they could be used in between gasket layers to control the height of the gel, but this made the stack too tall and required two rounds of UV and flipping the stack in between rounds to get both sides. Ultimately, the simplest solution was to keep the gasket layer as thin as possible, dispense gel solution through the gap, UV, then biopsy punch the final cylinder for a clean encapsulation product.