Flexible antenna holds promise for wearable health monitoring

Because wearable systems can be subject to a variety of stresses as patients move around, the team set out to create a device that could be stretched, rolled or twisted, but would always return to its original shape. To begin, lead researcher Dr Yong Zhu and his team poured a liquid polymer over a series of silver nanowires arranged in a particular pattern. When the polymer was set, it formed an elastic composite material that formed the radiating element of a microstrip patch antenna. By manipulating the shape and dimensions of the radiating element, the researchers found they could control the frequency at which the antenna sent and received signals. They also discovered that although the antenna's frequency changed as it was stretched, the frequency always remained within a defined bandwidth. "This means it will still communicate effectively with remote equipment while being stretched," Dr Zhu explained. "In addition, it returns to its original shape and continues to work even after it has been significantly deformed, bent, twisted or rolled." While other researchers have developed stretchable sensors for wearable health systems, Zhu believes theirs is the first with the ability to be integrated into such devices to transmit data from the sensors, so that patients can be monitored or diagnosed. What's more, the production method is said to be relatively simple and easy to scale up.