Investigation of graphene piezoresistors for use as strain gauge sensors

Abstract

The primary objective of this research is to fabricate a graphene-based piezoresistive strain gauge and characterize its sensitivity. The strain gauge consists of mechanically exfoliated graphene sheets and electrical electrodes located on a silicon wafer. Instead of using e-beam lithography, which is the most widely applied methods in experimental studies of graphene, a new fabrication method utilizing conventional photolithography was used to easily fabricate a new nanoelectromechanical system strain gauge. The proposed fabrication technique is easy and only requires a few types of microfabrication equipment, thereby opening up a new way to broadly spread and facilitate associated graphene research, especially for those laboratories with limited resources. To characterize the piezoresistive sensitivity of the graphene-based strain gauge, a strain-detection system built by an equivalent-stress macrocantilever was set up to generate mechanical bending strain where a calibrated commercial strain gauge was packaged to display the generated strain. Utilizing this measurement setup, the electrical properties of the graphene-based piezoresistive strain gauge were reliably investigated. A high gauge factor of ∼150 was experimentally measured with the graphene device, which promises a new strain gauge of high sensitivity.

Simulation of Graphene Piezoresistivity Based on Density Functional Calculations

“…Lee et al reported that the gauge factor of graphene grown on Ni and Cu films by chemical vapor deposition was 6.1, with 1% applied strain [3]. Chen et al found that the gauge factor of mechanically exfoliated graphene was nearly 150 [4]. Hosseinzadegan et al reported that the gauge factor of graphene prepared by chemical vapor deposition on Si/SiO 2 wafer was 18,000 [5].…”

Stretchable and highly sensitive graphene-on-polymer strain sensors

“…nanoparticles 1 , nanotubes 2 , nanowires 3 4 5 , thin films 6 7 8 ) and their assemblages have been attracting interest recently due to their strain sensing characteristics. For example, strain sensors comprised of carbon nanotubes (CNTs) 6 7 8 9 10 11 12 13 14 , zinc oxide nanowires 4 5 , or graphene 15 16 17 18 19 20 21 serve as good alternatives for developing new sensors because of their outstanding properties. For graphene-based sensors, the principal vibrational frequencies 15 and electrical conductance 16 of graphene strongly depend on its topological structure which can be modulated by applying uniaxial strain, making it useful for high sensitivity tensile strain sensing.…”

A Review of Chipless Remote Sensing Solutions Based on RFID Technology

“…Strain sensing is possible in graphene through several different methods. These include embedding GO in a stretchable polymer matrix, as seen in Reference [295] by Li et al and also in Reference [292] by Qin et al Further discussion on the stretchability of the C-C bonds in the embedded graphene can be found in the work of Chen et al [302]. Other methods involve the use of nanographene films with discrete islands in the film.…”

“…Other sensors have been outlined that use rGO for the sensing of gasses, such as NO 2 , NH 3 and CO, such as those found in the works of Le et al [287] and that of Lu et al [305]. It should be noted at this point that GO is itself hydrophilic [302] due to the presence of hydrophilic functional groups on its surface [287] and regular graphene exhibits quantum capacitive effects when exposed to humid environments [287,299]. Furthermore, the complete reduction of GO in some cases can be very difficult to achieve [297] and the use of this partial rGO is quite suitable for humidity sensing [304].…”