Touch is a very refined sense of the human body. However imperceptible many times, the fingertips can register minute variations on a surface. In this sense, a research has just demonstrated that fingers can perceive changes of just one atom in the molecule of a certain material.

To do this, researchers at the University of Delaware used microlayers of silane, a silicon-derived material to test finger sensitivity. The researchers placed these single layers of silane on top of a surface that was smoother than human perception. This was to avoid confusion with the material being tested.

Image: PublicDomainPictures/Pixabay

After that, a volunteer person ran his finger over the surface and from that the authors performed mathematical analysis about the answers. It turned out that in 68% of the cases, the finger touch was able to differentiate very similar materials.

Some of these tested materials (silane with slight variations) changed by only one atom. For example, there was an exchange in the molecule between a nitrogen atom and a carbon atom. Impressively, the researchers were therefore able to conclude that fingers can distinguish even this exchange of only one atom within the material molecule.

The study shows, therefore, that parts of the human body can perceive not only physical variations (such as shape and temperature) but also chemical ones, in the composition of the molecule itself.

Finger sensitivity and brain interpretation

When you touch something, your fingers send a signal to the brain. This signal only reaches your nervous system through an intricate set of neurons and nerves. Once in the brain, your gray matter interprets what is happening and sends a signal back, indicating a reaction. This phenomenon, which is called arc-reflex, happens in milliseconds and is involuntary.

Image: Colin Behrens/Pixabay

However, knowing the chemical differentiation of our touch, materials engineering may have a completely new field of research. Charles Dhong, lead author of the research, states, for example, that from this knowledge it will be possible to create super-realistic textures for virtual reality.

Dhong says, in this regard, that the possibilities are not yet quite clear. However, chemically modelling materials for touch should create innovative new technologies exploiting this sense, at your fingertips.

The article is available in the journal Soft Matter.