As a fundamental physical process, friction is an essential characteristic of the mechanical interaction between contacting bodies and their surfaces. Indeed, it is only theoretically possible to assume perfectly smooth surfaces that do not experience friction, since in practice achieving such a condition seems impossible or extremely difficult. Friction between bodies occurs when the smallest protrusions, pores, or micro spikes on their surfaces contact each other, due to which adhesion is formed.
The critical question is to determine whether friction is a desirable process. To state that this phenomenon is bad or good seems inappropriate in a general context since friction can be both good and bad, depending on the conditions. When a person runs a marathon or a car drives on the road, friction plays a good role because it increases the grip between the foot (wheel) and the road. As a result, the runner (car) can bounce harder off the road surface. On the other hand, friction in bearings can slow down the rotation of the primary mechanism or lead to overheating of car parts during their active operation. In such cases, friction must be reduced.
By now, technological advances offer several advanced ways to reduce or increase friction force. It is possible to reduce friction by using unique lubricating solutions covering surface roughnesses (7 methods, 2020). This has value for bearings and door hinges. More innovative methods to reduce friction include using a streamlined body shape — especially for liquids and air media — or reducing contact between bodies, including using a magnetic cushion. This is typical for trains, which can have a streamlined, elongated shape — to overcome air friction — and have no physical contact with the rails but communicate with them through magnetic levitation: this requires charging both bodies equally. On the contrary, to increase friction, it is enough to make the shape of the body rougher. For instance, the surface of the most advanced running shoes has many microspikes. At the same time, it is acceptable to increase the pressure on the body to increase the friction force: using this method is appropriate when there is a need for rigid traction of the truck (Veerendra, 2020). Interestingly, it is also possible to increase friction by reducing smoothness: a slippery road can be sprinkled with sand so that people do not slip on it.
References
Veerendra. (2020). Ways of increasing friction and reducing friction. AplusTopper. Web.
7 methods of reducing friction. (2020). DewWool. Web.