Flexing a way forward for wearable electronics

From smart skin patches to wearable health monitoring devices, flexible electronics have revolutionized how people and technology interact. But even the most conductive polymer — poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) — has struggled, because of its inherent brittleness and limited stretchability, to meet arduous monitoring demands, which require bending, twisting, and even tissue-like healing. Previous efforts to improve flexibility through additives have resulted in compromised conductivity, biocompatibility concerns, or limited self-repair capabilities.

Chen et al. used a polar solvent-enhanced strategy to systematically optimize PEDOT:PSS film, enhancing chain rearrangement and dynamic hydrogen bond reformation within the polymer network. The resulting conductive film demonstrated high conductivity, mechanical flexibility, self-healing ability at room temperature, and excellent biocompatibility.

“This elegant yet accessible fabrication strategy demonstrates that advanced performance can arise from a simple processing approach,” said author Manish K. Tiwari.

Using a sensor attached to human skin with surgical tape, the researchers evaluated the film’s capability for monitoring movements by detecting motion-induced strain from joints. Under repeated deformation, the sensor consistently detected both large joint movements and subtle facial expressions.

“Our work highlights how the approach can achieve a balance between conductivity and stretchability, effectively overcoming long-standing trade-offs in PEDOT:PSS-based systems,” said Tiwari. “For clinicians, this may be a step toward developing real-time motion monitoring tools that can support rehabilitation and other personalized healthcare applications.”

The researchers hope to build on their success by working to minimize hysteresis, a “lagging” effect, and integrating wireless connectivity for seamless, long-term motion monitoring.

“With these advancements, the device could represent the next generation of intelligent, self-healing wearables, bringing adaptive electronic functionality ever closer to human skin,” said Tiwari.

Source: “Polar solvent-enhanced PEDOT:PSS based elastomer as a self-healing film for strain sensing and human motion monitoring,” by Wenqing Chen, Wei Huang, Abbas Heydari, Eirini Velliou, and Manish K. Tiwari, APL Electronic Devices (2025). The article can be accessed at: https://doi.org/10.1063/5.0301081 .