By Dave DeFusco

A new material called OXene could change the way electronic devices interface with living tissues, according to the PNAS paper “Symmetry Engineering in 2D Bioelectronics Facilitating Augmented Biosensing Interfaces.”

This innovative material is derived from MXene—a type of two-dimensional material known for its electrical conductivity—but with an added twist: symmetry-breaking, meaning the material’s structure intentionally disrupts the balance of electrons to improve its ability to conduct electricity and respond to mechanical stimuli.

Symmetry breaking enables better signal transmission and energy conversion than conventional materials. As a result, OXene shows promise in applications like piezoelectric devices, which generate electrical energy from movement. This unique design enhances OXene’s performance, enabling new functions, such as advanced biosensors, wireless medical implants and high-precision physiological monitoring.

“This research underscores the potential of symmetry engineering as a game-changer for future bioelectronics,” said Dr. Wubin Bai, senior author of the paper and an assistant professor in the Department of Applied Physical Sciences. “By strategically altering the molecular structure of materials like OXene, we can unlock new ways to enhance energy efficiency, signal transmission and computational power in medical devices.”

The researchers behind the breakthrough combined two types of symmetry-breaking—orbital symmetry and inverse symmetry—to enhance OXene’s ability to reduce electrical resistance and improve signal quality. This combination allows the material to interface seamlessly with biological tissues, making it highly effective for medical devices.

OXene’s versatile properties enable it to excel in a variety of bioelectronic applications, such as:

• Bioelectrode Arrays: Used for high-resolution brain and heart monitoring.
• Wireless Medical Implants: Devices capable of transmitting physiological data without wires.
• Gait Analysis Systems: Sensors that monitor body movement in real time.
• Smart Transistor Matrices: Reconfigurable electronic circuits that can adjust to different tasks.

The material was tested on heart tissues from rodents and pigs, demonstrating the ability to capture detailed, high-quality physiological recordings. By integrating these recordings with machine learning algorithms, the researchers were able to predict heart conditions with impressive accuracy, showing how OXene-based devices could assist in real-time health monitoring.

The creation of OXene involves a three-step process: MXene processing – preparing the conductive base material; laser cutting— precisely defining shapes to customize the material’s structure; and oxygen plasma treatment, which is a controlled oxidation process that enhances OXene’s electrical properties by creating polar structures on the material’s surface.

This unique configuration reduces electrical resistance, improving the material’s performance compared to traditional bioelectronic components, such as gold or polymers. It also incorporates Schottky junctions, which are semiconductor-metal interfaces that further enhance OXene’s electrical behavior and piezoelectric response, enabling self-powered medical devices. This could result in untethered implants and wearable technologies that don’t rely on external power sources.

“By providing stable, high-fidelity signal transmission, OXene could pave the way for new medical devices, such as brain stimulators for Parkinson’s disease and cardiac patches that help monitor heart rhythms wirelessly,” said Dr. Yizhang Wu, first author of the paper and a postdoctoral research fellow at UNC-Chapel Hill. “With its potential for clinical applications, OXene represents a significant step forward in developing medical technologies that are smarter, safer and more effective.”

November 19, 2024