How is tribology linked to sustainability?
The first thing that comes to mind is usually
“lower friction leads to lower energy losses and a higher energy efficiency”.
That is true, but tribology has many more roles in sustainability. One of them is that a good tribological performance is often necessary to enable other sustainable technology to be used and make a difference. In fact, without adequate tribological performance, much-needed technological transitions may be delayed or, in worst case, they will never take place. That would mean serious setbacks in our combat against climate change, at a cost we simply cannot afford.
Can tribology really be a crucial enabling factor for emerging and promising sustainable technology? Indeed it can. Look for example on the unleaded gasoline or alcohol-based fuels we use today. In hindsight, they seem obvious and not too adventurous transitions to undertake. But actually, they both required much material development and tribological optimization before the system around the fuels eventually allowed them to compete with traditional fuels (and in some respects, the combat is still not over). History is full similar transitions where obstacles have complicated the way towards acceptance, profit (always a component), and widespread use. Optimizing tribological performance can straighten the journey and allow sustainable technology to make a difference soon – which is what we need today.
Part of a tribological optimization is to maximize the lifetime of components using thin surface films, called tribofilms, that grow on the surfaces during use. They can be controlled to minimize wear or minimize frictional heat generation. Efficient tribofilms mean the mechanical work can be handled by smaller systems, which means that manufacturing needs less material and that energy can be saved.
Manufacturing is one thing, energy efficiency during use is another. Wear resistance and long lifetimes are most helpful if they are combined with energy efficiency during use. Remember the friction in the beginning? This is when that contribution becomes important. It does indeed play an important role when successfully stretching a circular economy to an energy efficient long elliptic lifecycle. But as described, low friction is only one of many roles tribology has in technology for tomorrows sustainable world.
Is then anyone of the roles more important? No, they are all important parts. But although long lifetimes and high energy efficiency strongly contribute to a sustainable world, enabling sustainable systems to become accepted, profitable and above all widely used must be the primary task for today’s research in tribology.