Improving the Sensing Properties of Graphene MEMS Pressure Sensor by Low-Temperature Annealing in Atmosphere

Abstract

The high demand for pressure devices with miniaturization and a wide bearing range has encouraged researchers to explore new high-performance sensors from different approaches. In this study, a sensitive element based on graphene in-plane compression properties for realizing pressure sensing is experimentally prepared using microelectromechanical systems (MEMS) fabrication technology; it consists of a 50 µm thick, 1400 µm wide square multilayer component membrane and a graphene monolayer with a meander pattern. The prepared sample is extensively characterized and analyzed by using various techniques, including atomic force microscopy, Raman spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, COMSOL finite element method, and density functional theory. The sensing performance of the new pressure sensor based on the sensitive element are obtained by theoretical analysis for electromechanical measurements of the sensitive element before and after low-temperature annealing in atmosphere. Results demonstrate that atmospheric annealing at 300 °C enhances the pressure sensing sensitivity by 4 times compared to pristine graphene without annealing, which benefits from the desorption of hydroxyl groups on the graphene surface during annealing. The sensitivity is comparable and even better than that of previous sensors based on graphene in-plane properties. Our results provide new insights into realizing high-performance MEMS devices based on 2D sensitive materials.

Differential pressure sensors based on transfer-free piezoresistive layered PdSe2 thin films

“…To obtain the strain under specific differential pressure, FEA was used to simulate the deformation of the SiN x membrane under the differential pressure, and the corresponding average stress can be calculated (figure 3(b)). By fitting the experiment data shown in figure 3(b), we obtain a GF of −43.3, which is ten times larger than that of some reported graphenes (GF = 0.8 ∼ 4.4) [12,15,26,34] and several times larger than some reported polycrystalline silicon films (GF = 8.8 ∼ 22) [35][36][37].…”

“…In this study, we report a highly sensitive MEMS differential pressure sensor based on a transfer-free ultrathin 2D PdSe 2 film, which is synthesized on a SiN x diaphragm by plasma-enhanced metal selenization (PES) at low temperature down to 200 °C. It can reach a sensitivity of 3.9 × 10 −4 kPa −1 at a differential pressure range of 0-60 kPa, which is better than the most currently reported 2D diaphragm pressure sensors [12,15,26]. Furthermore, based on a Wheatstone bridge circuit, the device can compensate for the temperature drift and keep excellent pressure monitoring capability.…”

An efficient pressure sensor based on environmental-friendly CNTs-graphene-PDMS film

“…But, the interface between flexible substrates and 1D materials, however, is not sufficiently strong, which affects the stability of the pressure sensors. As a result, extra treatments, like thermal annealing, are needed to improve the performance [32]. Therefore, in order to avoid additional treatment processes, 2D material, graphene, is used that can offer a large contact area with the substrate [33].…”

Nanoscale mass measurement based on suspended graphene

“…to identify single-layer graphene and probe the key physical properties of its distinctive G, D and 2D peaks (around 1580 cm −1 , 1360 cm −1 and 2700 cm −1 , respectively [16][17][18][19][20][21][22]). The G peak corresponds to the E 2g phonon at the Brillouin zone (BZ) center, reflecting the layer of graphene.…”