We live in an era where technology is leveraged to meet our on-the-go needs. Mobile workstations, exercise equipment, and constant health tracking devices have carved out a booming health tech industry, transforming the way we all think about daily life. 

According to MarketWatch, the wearable health devices market is projected to reach $56.6 billion globally by 2030 from $17.4 billion in 2020, at a combined annual growth rate (CAGR) of 19.5 percent. The growing adoption of mobile platforms, artificial intelligence, 5G, and the preference for home healthcare will likely continue to boost this market.

Activity monitors and trackers (e.g., smartwatches) accounted for the largest market share in 2020, the same MarketWatch report states. And one of the latest emerging multi-functionality devices to track our health is a recent innovation from Dr. Huanan Zhang of the University of Utah College of Engineering, highlighted in a recent issue of APL Materials. 

Dr. Zhang and his team have developed a novel, screen-printed nanoparticle biosensor for cotton/polyester blended clothing—such as a compression sleeve—to act as wearable electromyography (EMG) and sense functional activities of muscles in real-time. With a wide range of potential clinical applications, such as muscle rehabilitation post-injury or post-surgery, this new technology provides a more cost-efficient, simple, user-friendly design to track muscle activity than traditional taped-on wires and electrodes on the surface of the skin. 

“Our material empowers clinicians to track a muscle’s long-term electrical signals with greater precision, allowing them to gain a better understanding of a patient’s journey and therapeutic outcomes over longer periods of time.” Dr. Zhang says.

Dr. Zhang and colleagues used silver flakes encapsulated with gold nanoparticles—which they coined “Au/Ag fabrics”—as the functional conductors of electrical activity released from the muscle fibers and absorbed within the compressive sleeve. These particles represent a viable option for manufacturing such a wearable sensor, as gold is highly biocompatible (doesn’t cause skin irritation or toxicity when worn) as opposed to silver alone. 

“The silver allows for greater conductivity, while the gold material contains high biocompatibility while improving the overall signal,” Dr. Zhang says.

In addition to demonstrating the efficacy of their new technology in detecting functional muscle activity, Dr. Zhang and his colleagues provided evidence that the material can be machine-washed several times (up to 15, in their study) without losing its efficacy. 

Could this emerging technology usher in an era of evolution for tracking our heart rate and rhythm, as well as muscle function, throughout the body through our clothing? 

Dr. Zhang envisions a day when this nanoparticle-printed clothing could interface with a smartwatch to provide real-time muscle activity readings. Looking beyond the arm sleeve the researchers tested in this preliminary study, there is certainly a possibility for this technology to make its way into other forms of tightly-fitted clothing, including compression shorts and pants, undershirts, and socks or leggings.