Thermally-Drawn Microelectronic Fibers Can Turn T-Shirts Into Sweat-Sampling Health Monitors
By integrating smart threads into its production, an entire t-shirt can be turned into a sensor with unrivaled coverage.
Researchers from Tohoku University's Frontier Research Institute for Interdisciplinary Sciences have developed a novel microelectronic fiber that, they say, can turn a t-shirt into a smart health sensor which samples the wearer's sweat.
"Our breakthrough is the first successful attempt at using thermally drawn fiber in wearable bioelectronics for monitoring biochemical signatures," claims Yuanyuan Guo, assistant professor and team lead, of the work. "Since most developments so far could not be considered clothes, we devoted our effort to transforming fiber, to make truly wearable smart fabric."
The fiber which makes the smart t-shirt smart was produced using a process known as "thermal drawing" in which heat is applied to a larger pre-form material made from polycarbonate with stainless steel and carbon black loaded polyethylene (CPE) running through it, allowing it to be pulled into a thinner thread suitable for micro-machining into a weave that can be integrated into worn fabrics.
Previously, most sweat-monitoring wearables have focused on patches which are added to fabrics or attached directly to the wearer's skin — but Guo and colleagues' creation has the potential to be applied to an entire garment, offering a dramatically increased sensing area with improved comfort.
To prove the concept, the team used a single strand of fiber to build a t-shirt capable of monitoring sodium and uric acid concentrations in the wearer's sweat. "This fiber-based wearable bioelectronics, integrated with the fully multiplexed electrochemical sensing, represents a new class of wearable health monitoring," the team concludes.
"By tuning and enriching the sensing materials for functionalization," the researchers continue, "the repertoire of the biochemicals in sweat, which can be detected via our fibers and textiles, will be expanded. In addition, not limited to biochemical parameters, physical parameters, such as pressure, temperature, and bioelectrical ones, can also be incorporated into fiber-based sensing systems, by designing new fiber geometries and incorporating new functional materials. In the future, such fiber-based bioelectronics holds great potential for fully comprehensive health monitoring applications in the daily life."
The team's work has been published in the journal Analytical and Bioanalytical Chemistry under open-access terms.