ZG Stardust

More than four thousand years ago, the silkworm Bombyx mori was domesticated and prized for its creation of white silk. Over the course of its life, each insect spins over one kilometer of pure thread into a cocoon—containing properties that manmade fibers have yet to achieve. This cocoon then provides protection against predators during one of the most interesting periods of the insect’s life—its metamorphosis from worm (larva) to moth (adult). Today, this species no longer exists in the wild, but is commonly bred by humans both as part of traditional economies around the world, and for the textile industry. There has also been increased interest in Bombyx mori as a model organism in biology.  

Recently, it has been demonstrated that several factors affect how the silkworm spins and the resulting rate and form. For instance, if flat surfaces are provided as scaffolds, the worm will also spin flat patches. Other factors, such as heat and light, also impact where a worm is likely to move along the scaffolding to begin spinning. One of the most consistent behaviors observed in worms in the fifth instar (larval stage) and ready to spin is the extreme desire to move upwards—as high as possible. The vertical migration suggests that worms can sense the effects of gravity, and change their behavior accordingly. It is thought that silkworms, like many other insects, have gravity sensing cells or tissues, such as Johnston’s Organ, which help detect mechanical signals.

In 2016, Chinese scientists took silkworms on the International Space Station as part of the Tiangong-2 laboratory to examine the production of cocoons in microgravity. While full data is not available, it was clear that the worms do spin and form cocoons with some degree of success. However, this remains one of the only studies to date that has explored the behavior of fabricating organisms in microgravity, and many questions unanswered. For instance, what impact does exposure to microgravity have on the worm once it returns to Earth? How does microgravity affect development in younger worms or eggs? And what new forms can be created in microgravity versus Earth gravity? 

In this project, we aim to explore these questions by exposing silkworms of all stages in the life cycle—egg, young larva, spinning larva, cocoon, and moth—to a microgravity environment through a parabolic flight. Insects within specially designed capsules will be examined and filmed aboard a unique aircraft as it completes many parabolic arcs. Over the course of the entire flight, insects will experience 15 rounds of zero gravity, for 20-30 seconds each time. We will correlate the image and video data to recorded accelerometer data, thereby elucidating the real time responses of organisms to drastic gravitational changes. Upon return, we will study the behavioral and morphological changes in the worms and moths in the f0 generation (those that flew) as well as the f1 generation, to evaluate any lasting effects. We will also examine the forms and quality of silk that will be generated on the flight and afterwards. 

This work fits within the sphere of insect-related projects conducted by the Mediated Matter group, which include Silk Pavilion I & II, Synthetic Apiary, and our recent Maiden Flight. Each project sought to examine a link between the local or global environment of an insect, and the emergence of or change in a particular behavior or metabolism. Silk Pavilion I & II are large-scale architectural installations that modify the scaffolding system available to silkworms in their spinning stage to yield flat patches of silk that are distributed to create a differentiated material and form. Synthetic Apiary, by contrast, was an exploration of an artificial environment for urban honeybees, another important insect fabricator whose history is intertwined with humans. Most recently, we conducted Maiden Flight, which was an experiment aboard the Blue Origin New Shepard vehicle which launched in spring 2018. In this project, queen honeybees and their accompanying nurse bees were placed in an "autonomous lab" capsule which supported them as they journeyed to the Kármán line and back, experiencing 10 minutes of zero gravity at the apex.