Does Spiderman have the best superpower? Spider silk is considered one of the strongest biological materials in the world. Ten times stronger than the Kevlar in bulletproof vests, it is little wonder why scientists are continually fascinated by spiders and the tangled webs they weave.
Now, with the advent of high precision 3D printing technologies, researchers from Massachusetts Institute of Technology are letting their fascination run wild and 3D printing synthetic web structures to not only design innovative new biomaterials, but also to better understand the building processes and design capabilities that embed our creepy crawly superheroes.
Studying spider silk proteins not only gives us a clue about the evolution of spiders but also important insight into the mechanical properties of spider webs. If scientists were able to reproduce the mechanical properties of spider silk they could create super materials used for space stations, airplanes or bridges.
To fully understand the mechanical properties of a spider web, the whole web needs to be studied, including web size and thread length. This is near impossible to recreate in the lab. However, with the help of 3D printers, scientists were able to build synthetic, idealised web structures to investigate and untangle the mechanical properties of spider webs.
Zhao Qin, lead author of the study explained, “Nature provides materials with amazing functions but without the recipe or manual that could explain how these abilities are reached. We looked at spider webs, which feature a unique geometry and have exceptional mechanical properties that are well suited for the spider’s foraging behaviour. There are different types of web structures, such as orb webs, funnel webs or tangle webs, all linked to different mechanical functions”.
So what’s the best mechanical recipe for a spider web? Turns out it depends on their environment and purpose. Spider webs frequently exposed to wind and rain have more varied thread diameters than webs mainly experiencing mechanical stress due to impact of small prey. Those kind of spider webs have much more uniform thread diameters.
He adds, “Such knowledge is not only crucial for understanding the spider’s adaptability but also provides an important blueprint of many engineering applications such as space exploration and defence systems that require structural materials with both high strength and low density. Moreover, our results help further the understanding of designing strong and light materials for extreme mechanical conditions, which may have a profound impact on engineering applications such as composite reinforcements and scaffolds for biomedical applications”.
So what is the future with 3D-printed spider webs? Qin’s team are currently working on several innovations using both real silk and 3D printed silk to design new composites and wearable or even implantable devices to monitor deformations of the human body. Besides material innovations, his team are developing methods and devices that can capture the structure of complex 3D natural spider webs, which will eventually lead to a better understanding of the building process and design philosophy in spider webs.
Hearing all this, I can’t help but wonder if one day, I will see Spiderman swinging from one building to the next.