There are plenty of devices that can detect and track pressure, temperature and humidity on their own, but one that can replicate even the sensory functions of human skin has never been fashioned, until now.

Using recyclable objects found in the kitchen, electrical engineers in Saudi Arabia developed an artificial sensor that reacts to stimuli the same way as human skin.

The extra special sensor, aptly called the Paper Skin, can measure humidity, proximity, pressure, temperature, pH and flow in real time. Because of its remarkable features, Paper Skin could one day transform the field of medicine and robotics by laying the foundations for flexible and wearable multipurpose sensors.

The Physics Behind The Paper Skin

More versatile sensors are being developed by other scientists, but the problem is, the items involved in making them are not easy to get. Some of these rare materials include gold nanoparticles and nanowire-based conductors. On the other hand, vacuum technology-processed papers sure are cheap, but have displayed limited functionalities.

The team of engineers from King Abdullah University of Science and Technology (KAUST) built the artificial skin through a process called garage fabrication approach - combining sticky tape, aluminum foil, sticky notes and sponges. It proves that with the right amount of science and the right set of skills, one can uncover a breakthrough from items that are probably just lying around the house.

The household objects were integrated into a paper-based platform connected to a device to perceive changes on electrical conductivity.

The team tapped into specific properties of the items, such as adsorption, elasticity, porosity and dimensions.

The sticky note was used to pick up humidity. To detect acidity, researchers colored the sticky note with an HB pencil. Sponges were used for pressure, while the aluminum foil was for motion.

Boosting humidity in the surroundings increased the Paper Skin's capacitance, or its ability to store an electrical charge. Being exposed to an acidic solution elevated its resistance, while an alkaline solution reduced it. The voltage was altered in response to temperature changes. Bringing a finger near the Paper Skin meanwhile affected its electromagnetic field and lowered its capacitance.

In the end, the team concluded that the device is capable of detecting more stimuli in real time.

What's The Next Step?

The team's work has the potential to revolutionize the electronics industry. It opens the door to commercially available and affordable, high-performance sensors.

KAUST's Muhammad Mustafa Hussain, one of the project researchers, said they are now working to overcome limitations on their way to developing a commercial product. The team has their eye on producing sensors for medical applications.

"The next stage will be to optimize the sensor's integration on this platform for applications in medical monitoring systems," said Hussain.

For that to happen, however, the team has to give the Paper Skin wireless capabilities. They also have to carry out testing to make sure that the device is reliable and to ascertain how long it can perform under severe bending.

The team's findings are all featured in the journal Advanced Materials Technologies.

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