Renewable Matter # 11 / July-August

The Demise of Screws and Nails

by Federico Pedrocchi

As big as a blender or a container, in between these two extremes a plethora of formats. 3D printers – a very hot topic at the moment – can build a lot of things: jewels and house walls, dental prostheses and car bodies.

The peculiar thing is that this tool enables those who have manufactured the same objects before to make the objects of their dreams that traditional tools did not allow them to make. Many artisans trying 3D printers discover this potential. It is also possible to go further, and here things become odder. Thomas Demand is a German artist focusing on the underground world of caves. Stalagmites, stalactites and those multi-layer knolls characterised by layers of sediments accumulated over the millennia. For millions of years, nature has been using 3D printing techniques: he builds his objects layer upon layer. So Demand is building beautiful caves using printers, of course. At the moment, he builds only 3-by-2 m dioramas, but following Christo’s logic, he could go much further. Therefore, we could have those caves that nature could have built, but did not. What next? Let’s wait and see.

These are innovations that can open up new worlds, that is, they do not limit themselves –although their potential is revolutionary – to enable us to make what has always been done with other methods. And so here we come to screws and nails. In museums of the most ancient civilizations we always find nails and even screw. Screws, at least wooden ones, are at least 2000-year old because it took a little bit of time to learn to build helicoidal shapes, while nails are obviously more intuitive but less effective in keeping things together. Well the future belongs to glues. A future managed by the materials science, which has changed the concept of glueyness. Advanced glues are based on materials that “interpret” the structure of materials to which they have to stick offering a so-called complementary surface. It is a little bit like climbing walls wearing sticky chewing gums and then you discover hard crampon boots that, adapting to the many juts in the rock face and ice walls, are much more efficient. At the University of Riken in Japan, they have manufactured a strip of sticky fabric able to hold several hundred kilos attached to glass. 

New types of glueyness show a wide-spreading trend that goes beyond screws and nails. Since in car accidents pedestrians are hit and thrown onto the road or against another car, some people (those at Google working on a self-driving car) are designing super sticky surfaces to install on cars’ bonnets in order to retain pedestrians and reduce damage. They hold several hundred kilos, but then they can be taken off as if they were Sellotape. This is crucial in the case of pedestrians stuck to bonnets, otherwise they would have to be buried with the cars. In case of minor injuries, their lives could change dramatically becoming rather boring because by being stuck to the bonnet and by obstructing the driver’s view, the car would end up being permanently parked with no chance to go for a spin.