Researchers at Boise State University have developed a breakthrough in wearable electronics: a multifunctional electronic tattoo (e‑tattoo) that integrates energy harvesting, energy storage, and real‑time biometric sensing into a single, skin‑conformal platform. The innovation leverages electrospun poly(vinyl butyral‑co‑vinyl alcohol‑co‑vinyl acetate) (PVBVA) fibers coated with titanium carbide (Ti₃C₂Tx) MXenes, offering a scalable, biocompatible, and durable alternative to conventional wearable devices that often rely on rigid substrates or external gels.
Electronic tattoos are ultra‑thin, flexible devices that adhere directly to the skin, enabling applications in health monitoring, human‑machine interfaces, and self‑powered systems. This work, led by Ph.D. student Ajay Pratap under the supervision of Prof. David Estrada of the Micron School of Materials Science and Engineering at Boise State University, demonstrates how advanced materials and additive manufacturing can produce high‑performance, skin‑compatible devices for next‑generation electronics.
By integrating MXene into electrospun PVBVA fibers, the team achieved energy harvesting via a triboelectric nanogenerator, which demonstrated a peak power density of 250 mW·m⁻². Unlike thermoelectric devices that rely on heat gradients or photovoltaics that require light, triboelectric nanogenerators harvest energy directly from
human motion, making them ideal for wearable systems. A parallel‑plate capacitor suitable for low‑power touch sensing and energy storage was integrated with the device. To illustrate biometric sensing, the team demonstrated the etattoo's realtime capture of electrocardiogram (ECG) and electromyography (EMG) signals, with high skin conformity and minimal signal degradation. Throughout all tests, the e‑tattoo maintained
mechanical flexibility, breathability, and adhesion over extended wear, even under stretching, compression, and twisting.
"This research highlights the promise of MXene‑polymer composites in creating multifunctional, skin‑conformal devices," said Ajay Pratap. "Our e‑tattoo integrates energy harvesting, storage, and biosignal monitoring into a single platform, paving the way for self‑powered wearable systems." Prof. Estrada said, "Ajay's work demonstrates how atomically thin materials can transform wearable electronics. By combining MXene with electrospun fibers, we've created a scalable, biocompatible system that advances health monitoring,
human‑machine interaction, and energy autonomy."
This breakthrough builds upon Estrada's team's previously published advances in MXene-based energy harvesting and storage. Earlier this year, the group demonstrated an eco‑friendly, printed triboelectric nanogenerator using MXene‑polymer composites for sustainable energy harvesting, as well as scalable MXene inks for next‑generation energy storage devices. Together, these works establish a cohesive research trajectory
in multifunctional, atomically thin materials, advancing Boise State's leadership in self‑powered wearable systems and energy‑autonomous electronics.
This research was supported by NASA EPSCoR, the U.S. Department of Energy, and key collaborators including Idaho National Laboratory, Rutgers University, and NASA Ames. The interdisciplinary team brought together expertise in materials science, biomedical engineering, and nanoelectronics.
