Carbon Nano Tube-Based Sensor Design for NEMS/MEMS Applications

Author(s):  
Rekha Devi ◽  
Sandeep Singh Gill

This chapter deals with designing CNT-based piezoresistive pressure sensors with different boss sizes and with different configurations designed for low pressure range. The purpose for this work is to show a NEMS-based pressure sensor, which was analyzed by using ANSYS 17 software. The different combination of the diaphragm shows the improved performance of the pressure sensor in the case of CNT as compare to the silicon. This chapter is organized in sections, where section 2 discusses the review of CNT based MEMS/NEM design process and applications, Section 3 elaborates the use of CNT materials for design piezoresistive pressure sensors, Section 4 discusses mathematical modeling and simulation of CNT-based piezoresistive pressure sensors, Section 5 examines the results and discussion in terms of linearity and sensitivity of designed sensor, and Section 6 consummates the chapter with the conclusion.

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000373-000378
Author(s):  
R. Otmani ◽  
N. Benmoussa ◽  
K. Ghaffour

Piezoresistive pressure sensors based on Silicon have a large thermal drift because of their high sensitivity to temperature (ten times more sensitive to temperature than metals). So the study of the thermal behavior of these sensors is essential to define the parameters that cause the drift of the output characteristics. In this study, we adopted the behavior of 2nd degree gauges depending on the temperature. Then we model the thermal behavior of the sensor and its characteristics.


1999 ◽  
Author(s):  
Todd F. Miller ◽  
David J. Monk ◽  
Gary O’Brien ◽  
William P. Eaton ◽  
James H. Smith

Abstract Surface micromachining is becoming increasingly popular for microelectromechanical systems (MEMS) and a new application for this process technology is pressure sensors. Uncompensated surface micromachined piezoresistive pressure sensors were fabricated by Sandia National Labs (SNL). Motorola packaged and tested the sensors over pressure, temperature and in a typical circuit application for noise characteristics. A brief overview of surface micromachining related to pressure sensors is described in the report along with the packaging and testing techniques used. The electrical data found is presented in a comparative manner between the surface micromachined SNL piezoresistive polysilicon pressure sensor and a bulk micromachined Motorola piezoresistive single crystal silicon pressure sensor.


Author(s):  
Tran Anh Vang ◽  
Xianmin Zhang ◽  
Benliang Zhu

The sensitivity and linearity trade-off problem has become the hotly important issues in designing the piezoresistive pressure sensors. To solve these trade-off problems, this paper presents the design, optimization, fabrication, and experiment of a novel piezoresistive pressure sensor for micro pressure measurement based on a combined cross beam - membrane and peninsula (CBMP) structure diaphragm. Through using finite element method (FEM), the proposed sensor performances as well as comparisons with other sensor structures are simulated and analyzed. Compared with the cross beam-membrane (CBM) structure, the sensitivity of CBMP structure sensor is increased about 38.7 % and nonlinearity error is reduced nearly 8%. In comparison with the peninsula structure, the maximum non-linearity error of CBMP sensor is decreased about 40% and the maximum deflection is extremely reduced 73%. Besides, the proposed sensor fabrication is performed on the n-type single crystal silicon wafer. The experimental results of the fabricated sensor with CBMP membrane has a high sensitivity of 23.4 mV/kPa and a low non-linearity of −0.53% FSS in the pressure range 0–10 kPa at the room temperature. According to the excellent performance, the sensor can be applied to measure micro-pressure lower than 10 kPa.


Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1103
Author(s):  
Jae Sang Heo ◽  
Keon Woo Lee ◽  
Jun Ho Lee ◽  
Seung Beom Shin ◽  
Jeong Wan Jo ◽  
...  

Among various wearable health-monitoring electronics, electronic textiles (e-textiles) have been considered as an appropriate alternative for a convenient self-diagnosis approach. However, for the realization of the wearable e-textiles capable of detecting subtle human physiological signals, the low-sensing performances still remain as a challenge. In this study, a fiber transistor-type ultra-sensitive pressure sensor (FTPS) with a new architecture that is thread-like suspended dry-spun carbon nanotube (CNT) fiber source (S)/drain (D) electrodes is proposed as the first proof of concept for the detection of very low-pressure stimuli. As a result, the pressure sensor shows an ultra-high sensitivity of ~3050 Pa−1 and a response/recovery time of 258/114 ms in the very low-pressure range of <300 Pa as the fiber transistor was operated in the linear region (VDS = −0.1 V). Also, it was observed that the pressure-sensing characteristics are highly dependent on the contact pressure between the top CNT fiber S/D electrodes and the single-walled carbon nanotubes (SWCNTs) channel layer due to the air-gap made by the suspended S/D electrode fibers on the channel layers of fiber transistors. Furthermore, due to their remarkable sensitivity in the low-pressure range, an acoustic wave that has a very tiny pressure could be detected using the FTPS.


2021 ◽  
Author(s):  
SUMIT KUMAR JINDAL ◽  
ISHAN PATEL ◽  
KRISH SETHI ◽  
SIMRIT KAUL ◽  
SREEKANTH P K ◽  
...  

Abstract Capacitive pressure sensors have become more popular as compared to piezoresistive pressure sensors as they yield superior sensitivity and lesser non-linearity. Efficient analysis for modelling capacitive pressure sensors is thus increasingly becoming more important due to their innumerable use cases. The higher sensitivity of square diaphragm for the same side length in comparison to circular diaphragm makes it ideal for sensor design. In this work, a complete formulation for analysis of capacitive pressure sensor with the square diaphragm in normal and touch mode operation has been presented as these two modes are established operating modes for these sensors. A comprehensive study of sensor parameters like capacitance, diaphragm deflection, capacitive and mechanical sensitivity has been formulated to aid the choice of sensor characteristics. This work also focuses on the method to determine core design parameters for optimal operation. Computationally complex methods have been used in the past for analysis of square diaphragms. In contrast to the finite element system, the analytical technique proposed in this study is less complex and computationally efficient (FEM). The results were computed and simulated using MATLAB.


2021 ◽  
Author(s):  
Mikhail Basov ◽  
Denis Prigodskiy

Abstract The investigation of the pressure sensor chip’s design developed for operation in ultralow differential pressure ranges has been conducted. The optimum geometry of a membrane has been defined using available technological resources. The pressure sensor chip with an area of 6.15х6.15 mm has an average sensitivity S of 34.5 mV/кPa/V at nonlinearity 2KNL = 0.81 %FS and thermal hysteresis up to 0.6 %FS was created. Owing to the chip connection with stop elements, the burst pressure reaches 450 кPa.


2021 ◽  
Author(s):  
Mikhail ◽  
Denis Prigodskiy

The investigation of the pressure sensor chip's design developed for operation in ultralow differential pressure ranges has been conducted. The optimum geometry of a diaphragm has been defined using available technological resources. The pressure sensor chip with an area of 6.15 × 6.15 mm has an average sensitivity S of 34.5 mV/ κPa/V at nonlinearity 2K NL = 0.81 %FS and thermal hysteresis up to 0.6 %FS was created. Owing to the chip connection with stop elements, the burst pressure reaches 450 κPa. The developed pressure sensor can be used in medicine, automotive industry and highly specialized scientific developments.


2021 ◽  
Vol 31 (12) ◽  
pp. 124002
Author(s):  
Jie Yu ◽  
Yulan Lu ◽  
Deyong Chen ◽  
Junbo Wang ◽  
Jian Chen ◽  
...  

Abstract High-pressure sensors enable expansive demands in ocean sciences, industrial controls, and oil explorations. Successful sensor realized in piezoresistive high-pressure sensors which suffer from the key issue of compromised accuracies due to serious temperature drifts. Herein, this paper presents a high accuracy resonant high-pressure sensor with the pressure range of 70 MPa. Different from conventional resonant high-pressure sensor, the developed sensor utilized a dual-resonator-cavity design to minimize temperature disturbances and improve the pressure sensitivities. Besides, four circle cavities were used to maintain a high vacuum level for resonators after anodic bonding process. In details, Dual resonators, which is parallelly placed in the tensile and compressive stresses areas of a rectangular pressure sensitive diaphragm, are separated vacuum-packaged in the parallel dual cavities. Thus, pressure under measurement bends the pressure sensitive diaphragm, producing an increased pressure sensitivity and a decreased temperature sensitivity by the differential outputs of the dual resonators. Parameterized mathematical models of the sensor were established and the parameters of the models were optimized to adjust the pressure sensitivities and the temperature sensitivities of the sensor. Simplified deep reactive ion etching was used to form the sensing structure of the sensor and only once anodic bonding was used to form vacuum packaging for the dual resonators. Experimental results confirmed that the Q values of the resonators were higher than 32 000. Besides, the temperature sensitivity of the sensor was reduced from 44 Hz °C−1 (494 ppm °C−1) to 1 Hz °C−1 (11 ppm °C−1) by the differential outputs of the dual resonators in the temperature range of −10 °C–60 °C under the pressure of 1000 kPa. In addition, the accuracy of the sensor was better than 0.02% FS within the pressure range of 110–6500 kPa and the temperature range of −10 °C–60 °C by using a polynomial algorithm.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiu-man Wang ◽  
Lu-qi Tao ◽  
Min Yuan ◽  
Ze-ping Wang ◽  
Jiabing Yu ◽  
...  

AbstractSensitivity and pressure range are two significant parameters of pressure sensors. Existing pressure sensors have difficulty achieving both high sensitivity and a wide pressure range. Therefore, we propose a new pressure sensor with a ternary nanocomposite Fe2O3/C@SnO2. The sea urchin-like Fe2O3 structure promotes signal transduction and protects Fe2O3 needles from mechanical breaking, while the acetylene carbon black improves the conductivity of Fe2O3. Moreover, one part of the SnO2 nanoparticles adheres to the surfaces of Fe2O3 needles and forms Fe2O3/SnO2 heterostructures, while its other part disperses into the carbon layer to form SnO2@C structure. Collectively, the synergistic effects of the three structures (Fe2O3/C, Fe2O3/SnO2 and SnO2@C) improves on the limited pressure response range of a single structure. The experimental results demonstrate that the Fe2O3/C@SnO2 pressure sensor exhibits high sensitivity (680 kPa−1), fast response (10 ms), broad range (up to 150 kPa), and good reproducibility (over 3500 cycles under a pressure of 110 kPa), implying that the new pressure sensor has wide application prospects especially in wearable electronic devices and health monitoring.


Sign in / Sign up

Export Citation Format

Share Document