Glue and Skin
Name: Max D.
How does glue stick to skin? Is there a way to
create a glue that sticks to everything else but not skin? how?
Most glues work on the principle that a fluid is able to fit into
the microscopic cracks and crevices of a surface. This fluid, under
the action of oxygen, heat, or some other molecule will then form
more chemical bonds and harden. Think of a bunch of rubber bands. As
a loose grouping, the rubber bands can penetrate into small holes,
or fit themselves into tight spaces (the microscopic cracks on the
surface of what it is you are trying to glue together). However, let
us say you then took a flame or a heat gun to the rubber bands so
that the pieces melted into each other. Now, because the bands are
linked to each other, they do not move as much. But if these pieces
of rubber were initially already partly found in cracks and
crevices, than they will be very difficult to pull out since they
are no longer as mobile once they have been melted together.
So the problem is that skin is very much a rough surface, full of
crevices and cavities in which the fluid glue can penetrate. Once
the glue hardens, the individual molecules of the glue bond to each
other, then the hardened glue is difficult to remove from the
crevices in the skin where it penetrated.
It might be possible to develop a glue that works on a different
principle. A glue could be made that would dissolve the surface of
the object(s) that has to be glued together. Then, when the glue
evaporates, the dissolved material will harden once again but the
two pieces will be penetrating into each other. The glue can then be
made such that it does not dissolve skin, but can dissolve some
other material. This is not economically feasible however as one
would have to develop a glue that can dissolve a wide variety of
objects (otherwise it would have limited use) while making sure that
it does not dissolve skin. Both because it is difficult to find such
a substance, and because it would have to be tailored to the
specific object to be glued - I don't think it would be a
commercially successful product.
Greg (Roberto Gregorius)
Glue sticks to skin (or any other material) if it forms some
sort of chemical bond to the material. This bond may be strong or
weak depending upon the chemical nature of the glue and the material.
One way to prevent the glue from sticking to the material is to
apply a thin layer of a coating that either does not stick to the
glue, or to the skin, or both. In the case of skin, a thin layer of
Vaseline, or mineral oil works well. Even some water based hand
creams also prevent sticking to the skin. You may have noticed that
if you try to apply a piece of adhesive tape to skin that is
"sweaty" that it won't stick. The principle is the same, but the
weak sticking layer is oil from your skin. You can use any "weak
sticking" film of any sort. For example, the Teflon "goop" plumbers
apply to pipe threads so that the pipe will not freeze up over time
is the same principle.
So the choice of the glue is less important that the barrier
film applied to the skin. Some examples: epoxy, Elmer's glue, and
"Crazy" glue all stick to skin very aggressively -- as well to most
other materials except maybe polyethylene. So the strategy for
keeping the glue from sticking to skin is to apply a lotion or
cream before exposing the skin to the glue. Note: it doesn't take
much to do the job, just a couple of drops rubbed into the skin
Update: June 2012