Unveiling the potential of radiofrequency-operated 2D biochemical sensor in the internet-of-things era

Since its emergence in the 1980s, radiofrequency (RF) technology has made remarkable strides in the field of sensing applications, gaining widespread recognition. Nowadays, wireless RF sensing systems, such as those based on LC resonators, and RF Identification (RFID) technology, have become an indispensable part of our daily lives, satisfying the ever-growing demands of the Internet of Things (IoT).

Over the past few years, a group of researchers from Tsinghua University and Leiden University, have been dedicatedly pursuing developments in the field of 2D RF biochemical sensors. Published in International Journal of Extreme Manufacturing (IF: 14.7), their latest review provides a comprehensive overview of the mechanisms of 2D RF sensors, delving into the current trends and challenges in RF sensing systems based on 2D materials and devices.

Dr. Honglei Xue, the first author of this article from Tsinghua University, expressed their excitement about the advancements, “these Breakthroughs undoubtedly open up new possibilities and potential in meeting the demands of the IoT era”.

Since the discovery of graphene through mechanical exfoliation in 2004, 2D materials have emerged as the ideal building blocks for high-sensitivity electronic sensors, due to their superior physical and chemical properties. Leveraging the remarkable mechanical attributes of 2D materials, the researchers have developed ultra-thin and flexible 2D biochemical sensors that intimately conform to the contours of biological tissues, making them highly suitable for wearable devices.

In recent years, significant progress has been made in the manufacturing of 2D materials and devices, particularly in high-quality large-area chemical vapor deposition and screen-printing techniques, offering economic efficiency and fostering hope for their long-term applications.

“The prevailing RF sensing technology primarily relies on physical quantity measurements.” said Prof. Wangyang Fu, an associate professor at Tsinghua University, “To develop RF sensing platforms customized for a wide range of life-related applications, including food safety, environmental monitoring, life science research, and medical diagnosis, it is crucial to emphasize the optimization of sensitivity and compatibility in biochemical sensing functional materials.”

In this review, Prof. Fu and his co-workers have meticulously explored the working mechanisms of 2D RF sensors, with a primary focus on impedance monitoring, encompassing resistance and capacitance variations, especially the quantum capacitance of 2D materials. The adsorption of target substances on the surface leads to interactions at the target substance/2D material interface, modulating the electrical properties of 2D materials. These modulations are then detected and read by resonant circuits. This review also introduces the novel sensing platform based on homodyne/heterodyne detection to detect the response of molecular dipoles, offering enhanced sensitivity, improved response and reduced noise interference.

The review highlights significant advancements made in various 2D RF biochemical sensing platforms, including graphene, transitional metal dichalcogenides (TMDs), 2D metal oxides, and 2D MXenes RF sensors. These platforms hold immense promise in revolutionizing various fields and transforming the landscape of sensing technology.

Despite the remarkable progress, there are still substantial challenges in the integration and large-scale production of 2D RF sensors, as they transition from laboratory research to industrial applications. According to Prof. Chen Wang at Tsinghua University and Prof. Grégory Schneider at Leiden University, co-authors of this review article, “Integrating 2D sensors, power supply devices, remote communication systems, and user-friendly readout software into a comprehensive system, as well as achieving large-scale industrial manufacturing, is a complex and arduous task that requires further in-depth research and relentless exploration.”

About IJEM:

International Journal of Extreme Manufacturing (IF: 14.7, 1st in the Engineering, Manufacturing category in JCR 2023) is a new multidisciplinary, double-anonymous peer-reviewed and diamond open-access without article processing charge journal uniquely covering the areas related to extreme manufacturing. The journal is devoted to publishing original articles and reviews of the highest quality and impact in the areas related to extreme manufacturing, ranging from fundamentals to process, measurement and systems, as well as materials, structures and devices with extreme functionalities.

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