Sensor technology is essential for high-tech equipment and smart devices to monitor their environment. With the rise of mobile devices and autonomous vehicles, sensors are now everywhere. Advances in AI have boosted demand for small, low-cost, high-performance sensors.

This trend began with microelectromechanical systems (MEMS) technology from 1990 to 2020, integrating various sensors like accelerometers, gyroscopes, and microphones into almost every mobile phone. These sensors are made in large volumes using semiconductor manufacturing methods.

The discovery of graphene and other two-dimensional (2D) materials is pushing sensor technology further. These materials can create ultra-thin sensor layers, enhancing sensitivity and offering unique properties.

However, challenges remain in proving the superiority of 2D sensors over current ones and achieving reliable mass production. The Graphene Flagship program (2013-2023) has explored these issues, aiming to bring advanced 2D material sensors closer to market. An open access paper was recently published in the journal 2D materials, summarizing efforts of the different sensor research groups within this program and their successes, with a focus on wafer-scale fabrication of 2D material sensors with electronic readout.

Figure: Wafer-scale 2D material sensors. From Peter G Steeneken et al 2025 2D Mater. 12 023002, DOI: 10.1088/2053-1583/adac73. Under CC BY 4.0 license.

The paper describes the difference between transfer-based and transfer-free production of 2D material sensors. Although both approaches have their advantages and drawbacks, the choice between one and the other depends on the type of device and its system integration with readout electronics, whereby the authors describe the choice methodology in the paper. The paper also describes the advantages of reading out the sensor data with CMOS integrated circuits, which demonstrates 2D material sensor compatibility with existing fabrication technologies, and also raises the technology readiness level (TRL) of 2D materials, moving them closer to industrial use.

The authors describe in detail the operation, advantages and drawbacks of various types of 2D material sensors, including pressure sensors, microphones, gas sensors and biosensors.

While lab demonstrations of 2D material sensors with high-end equipment can reach technology readiness level (TRL) 3-4, advancing to TRL 5-6 and beyond requires validation in real-world environments. This involves integrating sensors, readout electronics, and data processing into portable prototypes. Wafer-scale sensor chips with electronic readout are advantageous due to their low cost, low power, and compact size. These can be made into compact sensor modules on PCBs, powered by batteries, and potentially enhanced with wireless interfaces and displays. An example of such a prototype is depicted in the figure below, which shows a graphene pressure sensor prototype with capacitive readout electronics, an Arduino processor, display and batteries.

Figure: 2D sensor prototypes. From Peter G Steeneken et al 2025 2D Mater. 12 023002, DOI: 10.1088/2053-1583/adac73. Under CC BY 4.0 license.

Twenty years after the discovery of graphene, and more than 10 years after starting the Graphene Flagship programme, significant progress has been made in realising 2D material sensors, and processes to produce them on wafer-scale. Graphenea offers a range of products that cater to the sensing community, such as various microchips containing devices geared towards gas, chemical and biosensing. Integration into experimental setups is made facile by supporting products such as the Graphenea card and cartridge. Nevertheless, although small-scale production has started, 2D material sensors are not in high-volume (1 million products per year) production at the moment.

Figure: Roadmap for bringing 2D material sensors to the market. From Peter G Steeneken et al 2025 2D Mater. 12 023002, DOI: 10.1088/2053-1583/adac73. Under CC BY 4.0 license.

The paper also contains a roadmap for increasing the TRL of graphene sensor products. To advance the industrialisation of 2D material sensors, more work is needed to increase their technology readiness level (TRL). Key challenges include proving that 2D sensors outperform current sensors and developing a cost-effective, scalable production process. Iterative testing and optimization of prototypes will help improve design and production methods, expediting adoption by large semiconductor and sensor companies.

A major challenge is bridging the gap between academic research and industrial product development. Companies prefer to minimize risks and will only invest heavily in 2D sensor technology after universities or startups demonstrate strong sensor performance. Once this gap is bridged, 2D sensors can be widely implemented in smart devices, speeding up their adoption.

2D sensors can replace current sensors, detecting smaller signals more reliably at lower costs and power. They can also enable new measuring techniques, such as single-molecule detection, leading to new applications. Examples include detecting plant diseases with biosensors, using gas sensors for health monitoring, and biometric sensors for personal identification.

Eventually, 2D sensors, enhanced by AI, can be integrated into IoT applications, sensor networks, autonomous vehicles, and robotics. High-density sensor deployment will improve environmental monitoring, benefiting agriculture, healthcare, and addressing societal challenges like climate change and resource scarcity. Consequently, 2D material sensor research is expected to continue growing and improving our lives.