Technology

Touchless Screens

The touchscreen tops himself: Novel displays are already responding to an approaching finger. Touch is no longer necessary. This ensures less wear and contamination and has plus hygienic advantages.

Touchscreens that are touched and wiped to control that particular program have been successful in many areas. Smartphones and tablets could hardly be operated differently.Grease and moisture of the fingers down on the display transfer, it is greasy, with time even rough and matt. The question is, what makes previously weak and requires a new purchase: the display or the battery.

In future it is likely to be only the battery. For displays of the future need for program control no more contact. It is enough near the surface to tap into the air or wipe. The Touchless screen, ie the contactless operation Monitor is feasible. That proved Researchers at the Max Planck Institute for Solid State Research in Stuttgart and the Department of Chemistry of the Ludwig Maximilian University of Munich.

Touchless Screens Development
Clearly ahead of its time the creator of these figures was on the canopy of the Stock Exchange in Frankfurt am Main (Hessen). The building was inaugurated in 1879, long before the invention of touch screen and tablet computers came. Max Planck researchers are currently working on Touchless screen, so that the devices could be controlled without direct skin contact – touching therefore soon be yesterday’s news.

Touchless Screens and humidity sensor

Initially, it was to develop a highly sensitive humidity sensor. They built it up from layers of antimony, phosphorus, oxygen and hydrogen atoms. “This material is known for some time that it can absorb moisture well,” said Pirmin Ganter, a doctoral student in the research group. It captures water molecules, reducing its electrical conductivity increases.

With this sensor, it showed that finger constantly release water molecules, though in almost infinitesimal quantities. This property, so they said, one could be used for a non-contact-to-use screen.

Contactless color change: A structure in which layers of antimony phosphate and oxide nanoparticles alternate, produced color in the same way as a butterfly wing or nacre. The color changes when it is approaching a finger to a few millimeters. Because the material then absorbs the moisture that gives the finger.
Contactless color change: A structure in which layers of antimony phosphate and oxide nanoparticles alternate, produced color in the same way as a butterfly wing or nacre. The color changes when it is approaching a finger to a few millimeters. Because the material then absorbs the moisture that gives the finger.

Amazingly quick response time

One was missing the researchers still: an acknowledgment that the approaching finger causes a reaction. Therefore, they modified the material so that it changes its color when the finger is close enough to the screen surface. This was achieved by installing additional layers of titanium and silicon dioxide. The material now used consists of more than ten layers that are barely a thousandth of a millimeter thick.

The reaction time of the material is astounding. While the original changes its conductivity after a few seconds, it takes only a few milliseconds in the Modified Version. Just as fast the water molecules escape again.

To bring the new display for series production, it still needs some time and an industrial partner. Many electronic devices could be equipped with touch-less screens. Especially for ticketing and ATMs they were hygienic reasons clear advantage. So bacteria could no longer be transmitted.