A spider web-inspired solution made possible using 3D printing could provide unprecedented protection for smartphone screens in the future.
Professors Frédérick Gosselin and Daniel Therriault, from Polytechnique Montréal’s Department of Mechanical Engineering, along with doctoral student Shibo Zou, have demonstrated how plastic webbing could be incorporated into a glass pane to prevent it from shattering on impact.
Their design was inspired by the amazing properties of natural spider webs. “A spider web can resist the impact of an insect colliding with it, due to its capacity to deform via sacrificial links at the molecular level, within silk proteins themselves,” said Professor Gosselin. “We were inspired by this property in our approach.”
The researchers used polycarbonate to achieve their results; when heated, polycarbonate becomes viscous like honey. Using a 3D printer, Professor Gosselin’s team harnessed this property to “weave” a series of fibres less than 2mm thick, then repeated the process by printing a new series of fibres in a perpendicular arrangement, moving rapidly before the entire web solidified.
It turned out that the magic is in the process itself, which is where the final product acquires its key properties. As the molten plastic is slowly extruded by the 3D printer to form a fibre, it creates circles that ultimately form a series of loops.
“Once hardened, these loops turn into sacrificial links that give the fibre additional strength. When impact occurs, those sacrificial links absorb energy and break to maintain the fibre’s overall integrity – similar to silk proteins,” Gosselin explained.
Shibo Zou, study lead author, used the opportunity to illustrate how such a web could behave when located inside a protective screen. After embedding a series of webs in transparent resin plates, he conducted impact tests with impressive results. Plastic wafers dispersed up to 96 per cent of impact energy without breaking and instead of cracking, they deformed in certain places, preserving the wafers’ overall integrity.
According to Professor Gosselin, this nature-inspired innovation could lead to the manufacture of a new type of bullet-proof glass or the production of more durable plastic protective smartphone screens. “It could also be used in aeronautics as a protective coating for aircraft engines,” Gosselin noted.
The team’s research continues, with their findings to date detailed in the October 2020 issue of Cell Reports Physical Science.