There are many adhesives in the world, aboutthe existence of which some people do not even suspect. For example, the international company Bostik produces the reusable sticky mass Blu Tack, which is positioned as a substitute for office buttons for attaching papers to the wall. Although this adhesive substance is reusable, it is simply impossible to call it reliable. However, researchers from the University of Pennsylvania and Lehigh University have developed a glue compound that is very strong and can easily be re-used.
They were inspired to create such glue by snails,which constantly exude mucus to prevent drying of their bodies and easy movement. Under adverse conditions, this mucus can take the form of a so-called epiphragm, a layer that penetrates the pores and surface irregularities and hardens. With the help of it, mollusks can firmly stick to trees and relive adverse conditions in safety. After the time the snails can weaken their “glue” with the help of moisture, and move on.
Is the best glue reusable?
Scientists under the guidance of the professor of the departmentchemical engineering Shu Yang found that the polymer polyhydroxyethyl methacrylate (pHEMA) has the same properties as snail epiphragm. In particular, we are talking about gaining stiffness during drying and elasticity when exposed to moisture - because of this, it can penetrate into the microscopic crevices of surfaces and firmly hold objects. When wet, it is easily peeled off, leaving no residue.
When it is hard, it is like a super glue, and does not allow to tear off the object. But in a magical way, you can soak it and see how it slips off without much effort, ”explained Professor Shu Young.
To prove the strength of a new type of glue glue,researcher Jason Christopher Jolly glued an insurance rope to the ceiling with pHEMA applied on a tiny adhesive patch. Strangely enough, the rope held him easily - this means that the glue created is, if not the best glue, but at least the strongest among the reusable ones.
Machine production will be cheaper and faster.
According to researchers based on pHEMAreusable glue can greatly simplify the assembly of cars and even reduce the cost of their production. Some elements of the machines are connected to each other with a strong adhesive, and unevenly gluing some part, you can irreversibly spoil the whole part. If pHEMA-based glue is used for this purpose, when errors occur, parts of the parts can be easily peeled off and put together again.
Disadvantages of reusable glue
Of course, scientists do not ignore a major weakness.New glue - when exposed to moisture, it immediately weakens. Because of this, car parts will need to be well sealed, and use during construction can be completely excluded. However, researchers do not intend to stop, and may well improve the technology.
This is not the first time that animals have inspiredscientists to create a sticky substance. In 2017, researchers at the South Korean University of Songjungwan created an underwater adhesive tape inspired by octopuses. You can read about it in our material.
Where do you think the glue created by snails can still be used? Write your suggestions in the comments, or in our Telegram-chat.