Researchers have developed a paper-based sensor that mimics the sensory functions of human skin using items found throughout your house.
Aluminum foil, Post-It notes, sponges and tape are usually not what would come to mind when thinking about embedded technology. However, a team of electrical engineers from the King Abdullah University of Science and Technology (KAUST) has successfully used these everyday materials to create a low-cost sensor capable of mimicking the human skin’s natural ability to feel sensations such as touch, pressure, temperature, acidity and humidity.
The aptly named Paper Skin performs as well as other artificial skin applications currently being developed while integrating multiple functions using cost-effective materials. Because of its unique features, Paper Skin could one day transform the field of medicine and robotics by laying the foundations for flexible and wearable multi-purpose sensors, including wireless monitoring of patient health and touch-free computer interfaces.
The engineers developed the artificial skin through a process called “a garage fabrication approach,” combining a bunch of things typically found in any kitchen drawer: tape, aluminum foil, sticky notes and sponges. These household items were then integrated into a paper-based platform connected to a device to perceive changes on electrical conductivity. The team tapped into specific properties of the objects, such as adsorption, elasticity, porosity and dimensions. Even more impressively, the total cost of goods to produce a a skin patch 6.5 centimeters on each side came to just $1.67.
Coloring a piece of the Post-It with an HB pencil allowed it to detect acidity levels, while sponges and wipes were used for pressure and aluminum foil for motion. Increasing levels of humidity, for instance, increased the platform’s ability to store an electrical charge, or its capacitance. What’s more, exposing the sensor to an acidic solution raised its resistance, while exposing it to an alkaline solution decreased it. Fluctuations in voltage were sensed with temperature changes. Bringing a finger closer to the platform disturbed its electromagnetic field, decreasing its capacitance.
While this innovation clearly has the potential to be revolutionarily, it still has to overcome a few challenges before a flexible, multi-functional sensory platform can become a commercial product. For this to happen, wireless interaction for the Paper Skin must be developed. Reliability tests also need to be conducted to assess how long the sensor can last and how good its performance is under severe bending conditions. From there, researchers hope to first employ the Paper Skin in the medical setting by monitoring real-time vital signs like heart rate, blood pressure, breathing patterns and movement.