Engineers tell spiders: I shall sing you the song of your people

Spiders have been weaving strands of silk extruded from their spinneret glands into intricate webs for approximately 100 million years. These 3D webs – which have various forms combining different types of silk – are used as both their shelter and their hunting ground.

Now, scientists have reported that they have translated the structure of a spiderweb into music, with applications beyond understanding arachnid behaviour, ranging from otherworldly composition to improved 3D printers.

“The spider lives in an environment of vibrating strings,” said Professor Markus Buehler, who led the project. “They don’t see very well, so they sense their world through vibrations, which have different frequencies.” These vibrations occur when a silk strand is disturbed, such as during construction or when knocked by the wind or a prey animal.

Buehler is a materials scientist and engineer known for working at the interface of art and science; last year he attracted attention for translating the coronavirus spike protein into music. In this project, he considered how to extract rhythms and melodies from spiderwebs: “Webs could be a new source for musical inspiration that is very different from the usual human experience.”

In addition to satisfying his own curiosity about music extracted from a non-human source, the project could give Buehler and his colleagues insights into the 3D architecture and construction of spiderwebs.

The MIT researchers built a digital model of a spider web, capturing cross sections with a sheet laser and reconstructing the 3D network with micro-scale resolution. This was in itself a challenge; the microscale size of the silk fibres and the complexity of structure make it challenging to quantify the structure and properties of webs.

They then assigned different frequencies (corresponding to notes) to strands of the web, using patterns in the 3D structure to generate melodies from these frequencies. They created a harp-like instrument and played the spiderweb-inspired music in several live performances.

They also scanned a web during construction, transforming each stage into music with different sounds to represent the spider’s progress in musical form. They hope that this step-by-step knowledge of how a spider builds its web could help devise 'spider-mimicking' 3D printers that build complex microelectronics.

“The spider’s way of 'printing' the web is remarkable because no support material is used, as is often needed in current 3D-printing methods,” Buehler said.

They also created a virtual reality (VR) setup to allow people to 'enter' the web. “The [VR] environment is really intriguing because your ears are going to pick up structural features that you might see but not immediately recognise,” said Buehler. “By hearing it and seeing it at the same time, you can really start to understand the environment the spider lives in.”

The researchers experimented with exposing the spiderweb to different forces and listening to how the music changed. “In the [VR] environment, we can begin to pull the web apart and, when we do that, the tension of the strings and the sound they produce change. At some point, the strands break and they make a snapping sound,” Buehler explained.

The MIT team are interested in learning how to communicate with spiders in their own 'language'; they recorded web vibrations produced when spiders performed various activities, such as web building or flirting. While the frequencies sound similar to the human ear, an algorithm could learn to classify the sounds into the different activities.

“Now we’re trying to generate synthetic signals to basically speak the language of the spider,” Buehler said. “If we can expose them to certain patterns or rhythms or vibrations, can we affect what they do and can we begin to communicate with them? Those are really exciting ideas.”