Stretchable Antenna Works as New Device to Monitor Health Issues

Today's medical and technological advances are helping many to more easily monitor health issues that might have previously gone undetected.

A recent study conducted by researchers from North Carolina University shows just how a new device can help out. When study participants began wearing  a newly developed, stretchable antenna that's incorporated into various wearable technologies, health officials were better able to monitor their health.

"Many researchers - including our lab - have developed prototype sensors for wearable health systems, but there was a clear need to develop antennas that can be easily incorporated into those systems to transmit data from the sensors, so that patients can be monitored or diagnosed," said Dr. Yong Zhu, an associate professor of mechanical and aerospace engineering at NC State and senior author of a paper describing the work, via a press release. 

It's important to remember that these devices must go everywhere with the patient. Thus, researchers worked to make them wearable at all times, even if a patient is in a stressful condition. 

For this, they used a stencil to apply silver nanowires via a specific pattern and then poured a liquid polymore over the nanowires. As the polymer sets, it forms an elastic composite material that helps the nanowires embedded in the desired pattern.

This patterned material forms the radiating element of a microstrip patch antenna that can be manipulated in both shape and dimensions to better control the frequency at which the antenna sends and receives signals.

The researchers also discovered that while the antenna's frequency does change as it's stretched, that frequency stays within a defined bandwidth.

"This means it will still communicate effectively with remote equipment while being stretched," said study author Jacob J. Adams, via the release. "In addition, it returns to its original shape and continues to work even after it has been significantly deformed, bent, twisted or rolled." As the frequency changes almost linearly with the strain, the antenna can be used a wireless strain sensor as well."

"Other researchers have developed stretchable sensors, using liquid metal, for example," Zhu added "Our technique is relatively simple, can be integrated directly into the sensors themselves, and would be fairly easy to scale up."

More information regarding the device can be found via the paper "Stretchable and Reversibly Deformable Radio Frequency Antennas Based on Silver Nanowires," published in the ACS Applied Materials & Interfaces.