Stretchable Antenna for Wearable Health Monitoring
With support from the National Science Foundation (NSF), researchers from North Carolina State University have developed a stretchable antenna that can be incorporated into wearable technologies, such as health monitoring devices. To create an appropriately resilient antenna, the researchers used a stencil to apply silver nanowires in a specific pattern and then poured a liquid polymer over the nanowires. When the polymer sets, it forms an elastic composite material that has the nanowires embedded in the desired pattern. This patterned material forms the radiating element of a microstrip patch antenna. By manipulating the shape and dimensions of the radiating element, the researchers can control the frequency at which the antenna sends and receives signals. The radiating layer is then bonded to a ground layer, which is made of the same composite, except it has a continuous layer of silver nanowires embedded. Since the frequency changes almost linearly with the strain, the antenna can be used a wireless strain sensor as well.