Nanoelectromechanical Sensors Based on Suspended 2D Materials

Abstract

The unique properties and atomic thickness of two-dimensional (2D) materials enable smaller and better nanoelectromechanical sensors with novel functionalities. During the last decade, many studies have successfully shown the feasibility of using suspended membranes of 2D materials in pressure sensors, microphones, accelerometers, and mass and gas sensors. In this review, we explain the different sensing concepts and give an overview of the relevant material properties, fabrication routes, and device operation principles. Finally, we discuss sensor readout and integration methods and provide comparisons against the state of the art to show both the challenges and promises of 2D material-based nanoelectromechanical sensing.

Dynamics of 2D material membranes

“…Third, further study of electrostatically coupled 2D materials can help to understand what ultimately limits the ultrafast relaxation times of these systems. Finally, we expect that smart engineering of mechanical resonators from heterostructures of 2D materials, can enable deeper insight and control over interactions at interfaces, which can bring significant improvements in device performance and lead to new functionalities [10].…”

“…As such, the membrane's motion is not only sensitive to the internal thermal, electric and magnetic processes in the membrane, but also to external forces from gases, liquids, charge and electromagnetic fields. A deeper understanding of the effects of these physical interactions on the mechanical motion and internal and external membrane processes can provide new methods for material characterization of atomically thin membranes, while at the same time offering a platform for enabling novel and improved environmental and force sensing applications, as has recently been reviewed [10].…”

“…The exfoliation of a single layer of graphite [1], and the demonstration of the unique properties of graphene [1][2][3][4], marked the start of an era where atomically thin crystalline materials can be studied and used for next generation devices [5][6][7][8][9][10]. Soon afterwards, this also led to the first mechanically movable structures of one atom thick graphene, which were shown to operate at high resonance frequencies in the MHz range [11].…”

Chemical Vapour Deposition of Graphene—Synthesis, Characterisation, and Applications: A Review

“…They presented the linearity between the NO 2 concentration and the sensor response, while the performance of the graphene-based sensor was evaluated in dry and humid conditions (0% and 50% humid environment) showing a less than 5% degradation in humidity, which is much lower than those of metal oxide gas sensors under the same conditions. Some excellent dedicated reviews about graphene in NEMS have been reported, discussing both NEMS and MEMS applications [238][239][240].…”

Development and Proof of Concept of a Miniaturized MEMS Quantum Tunneling Accelerometer Based on PtC Tips by Focused Ion Beam 3D Nano-Patterning

“…The use of optical transducer principles is shown to be unsuitable for a harsh environment and has limited potential for the system integration [ 3 ]. Furthermore, a new approach of accelerometers miniaturization methods uses thin graphene beams and their piezoresistive characteristic [ 22 , 23 ]. Recently, Fan et al [ 24 ] showed the suspension of a proof mass on a monolayer graphene beam thereby reducing the total area of the spring-mass structure in the range below 100 × 100 µm 2 .…”