A stretchable sensor developed by Researchers at North Carolina State University that has an unprecedented combination of sensitivity and proximity, allowing it to detect even the smallest changes in strain and range of motion beyond technology. Researchers have demonstrated the value of sensors by creating new health monitoring and human computing devices.
Food is a measure of how much something breaks down from its original length. For example, if you stretch a rubber band twice its original length, the deformation will be 100%.
“Blood pressure measurement is useful in many applications, such as blood pressure measuring devices and technologies that follow physical movements,” said Yong Zhu, co-author of the paper and professor says emeritus Andrew A. Adams of Mechanical and Aerospace Engineering at NC State.
But so far there is agreement Sensory sensors – able to detect small deformations – cannot be extended properly. On the other hand, long-range sensors are generally less sensitive. The new sensor we developed is sensitive and can withstand large deformations,” Zhu explains. “Another plus is that the sensor is strong even when transported, which means it is unlikely to break when pressure is suddenly applied beyond the threshold of perception.”
The new sensor consists of a network of silver nanowires embedded in a flexible polymer and the polymer has a pattern of parallelism of the same depth, turning on both sides of the object: cut left, next right, next left, etc.
“This feature – this creep – is what allows for great deformation without distracting,” says Shuang Wu, who is the first author of the paper and a recent Ph.D. graduated from NC State.
The sensor measures the problem by measuring changes in electrical resistance. As the material stretches, the resistance increases. The reduction in the surface of the sensor depends on the direction in which it extends. This does two things. First, the cut allows the sensor to adjust properly. Because the surfaces are open, creating a zigzag pattern, the material can withstand large deformations without reaching a breaking point. Second, when the cut is open, it forces the electrical signal to continue, up and down zigzag.
“To demonstrate the sensitivity of the new sensors, we used them to develop a new blood pressure monitor,” says Zhu. “And to show how disabled sensors can be, we created a wearable device to monitor movement on the human back, which has benefits for physical therapy.”
“We also demonstrated the use of human and machine tools,” says Wu. “Specifically, we’re using sensors to create a three-dimensional touch controller that can be used to control video games.”
“The sensor can be easily embedded into existing materials such as fabric and sports tape, ideal for practical applications,” Zhu said. “All this is just to criticize the surface. We believe that there will be many additional applications as we continue to work on this technology.
