Introduction:
In June of 2023, as part of a Brittingham grant, scientific glassblower Aaron Kirchhoff (Strong Force Scientific Glass) was invited to the University of Wisconsin-Madison for 5-days to create Blaschka invertebrate models. After investigation, Aaron decided on the creation of a Blaschka jellyfish model (Cyanea capillata) using a modern torch and adhesives.
In this investigation, Lauscha soft glass tubing was used, and a modern Herbert-Arnold torch was used for blowing and shaping the tubing. Even with modern technology and glass, the Blaschka invertebrate models still require a high level of technical skill and problem solving to create. Highlighted below are the construction methods Aaron Kirchhoff and Tracy Drier used to create a modern Cyanea capillata model.
Aaron Kirchhoff and Tracy Drier began their investigation by visiting the UW Zoological Museum to take a close look at the models in the UW collection, take detailed photos of models, and determine which model they were most interested in making. Throughout the week, they would return to the museum periodically when they arrived at uncertainties about how to construct their model. Ultimately, Kirchhoff chose the Cyanea capillata model due to a previous publication (linked here) made by UW Blaschka collaborators that proposed construction techniques for the Cyanea capillata and several other Blaschka models.
Jellyfish Body:
Kirchhoff began by blowing bubbles for the large dome of the jellyfish model, measured to about 85 mm in diameter. The bottom end of the bubble, near the stem, is heated and pushed in slightly to replicate the domed appearance of a jellyfish body. The bubble is then cut into two sections on the saw, so that the inner piece can fit inside the large outer dome. The images below depict where the bubble is sawed to create the jellyfish body. Although only one large bubble is needed for the model, multiple bubbles were made due to improper fit of the 2 pieces and glass cracking during sawing.
The model is supported by a 3mm metal wire. A bead of glass is wound around this wire and a trumpet-shaped piece of glass rests on this bead. This trumpet shape is a piece of architecture that supports the model body and inner components rather than an anatomical feature
Inner Components:
Several components are nested underneath the dome of the Cyanea capillata model. These components consist of nested ruffled tubes, small hollow tadpole shapes, tentacles, and hollow arced floats.
Ruffled tubes and hollow tadpole shapes:
Five ruffled tubes are present underneath the dome of the Cyanea capillata model. These tubes measure about 45-50mm in length, with the diameter of the top measured at about 22mm in diameter and the bottom at about 28mm in diameter. One smaller ruffled tube is nested inside this to add fullness and dimensionality.
Small glass tadpole shapes fit between the ruffled tubes on the final model.
Tentacles:
The Cyanea capillata model also contains over 100 tentacles adhered to the inner dome of the model. These tentacles were constructed by creating 5 foot sections of glass coated copper wire that were then cut down into sections of about 250-260mm in length. These wires were glued in bunches of 12-18, then these bunches were adhered to the inner dome of the model. The wire on the original model is 0.2mm, but 0.5mm was used for this project.
Arced floats:
Arced floats are adhered around the circumference of the inner dome of the model. These arced floats consist of small, hollow, kidney-bean shaped glass pieces measuring about 25 mm in length. These arced floats hide all evidence of construction on the model.
Assembly:
Once all the components were made, Drier and Kirchhoff could begin assembling the model. A glass bead was placed around a piece of metal wire to hold up the model on the stand. To show the inner anatomy of the jellyfish, dabs of silicone were placed on the inner dome of the model. This also highlighted the two-part construction of the dome. Drier and Kirchhoff used UV glue, a quick-set resin adhesive that cures with a UV light, to adhere each of the parts of the model together. The photo on the right documents the process of adhering the parts of the model together.
Tentacles were only put around half of the jellyfish. This allows the viewer to easily see the internal parts of the model and model architecture.
The final model was intentionally left unpainted for visual clarity of construction.
