Wide Range Highly Sensitive Pressure Sensor Based on Heated Micromachined Arch Beam

Author(s):  
Nouha Alcheikh ◽  
Amal Z. Hajjaj ◽  
Mohammad I. Younis

Abstract Miniaturized air-pressure sensing devices has received increasing attention during the past few decades. Pressure sensors have been explored in various potential applications, such as industrial control, healthcare, medical testing, and environmental monitoring [1–2]. Different sensing mechanisms and designs have been used for the detection of air-pressure. Of particular importance are resonant pressure sensors based on tracking the change in resonance frequency of the device with pressure. To improve the pressure sensor sensitivity, various designs have been investigated including carbon nanotubes, microcantilever, and bridge resonators. In a recent study [3], we showed a resonant pressure sensor based on an electrothermally heated clamped-clamped straight beam (cooling effect). We showed that operating the resonator near the buckling point maximizes its sensitivity [3]. In this work, we will focus on the detection of air pressure using an electrothermally heated initially curved beam exhibiting veering among its first two symmetric vibration modes, which offers more continuity in frequency variations, and hence measurements compared to buckled beams. The presented approach shows significant advantages in term of sensitivity and wide pressure range.

2013 ◽  
Vol 313-314 ◽  
pp. 666-670 ◽  
Author(s):  
K.J. Suja ◽  
Bhanu Pratap Chaudhary ◽  
Rama Komaragiri

MEMS (Micro Electro Mechanical System) are usually defined as highly miniaturized devices combining both electrical and mechanical components that are fabricated using integrated circuit batch processing techniques. Pressure sensors are usually manufactured using square or circular diaphragms of constant thickness in the order of few microns. In this work, a comparison between circular diaphragm and square diaphragm indicates that square diaphragm has better perspectives. A new method for designing diaphragm of the Piezoresistive pressure sensor for linearity over a wide pressure range (approximately double) is designed, simulated and compared with existing single diaphragm design with respect to diaphragm deflection and sensor output voltage.


Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6588
Author(s):  
Jun Ho Lee ◽  
Jae Sang Heo ◽  
Keon Woo Lee ◽  
Jae Cheol Shin ◽  
Jeong-Wan Jo ◽  
...  

For wearable health monitoring systems and soft robotics, stretchable/flexible pressure sensors have continuously drawn attention owing to a wide range of potential applications such as the detection of human physiological and activity signals, and electronic skin (e-skin). Here, we demonstrated a highly stretchable pressure sensor using silver nanowires (AgNWs) and photo-patternable polyurethane acrylate (PUA). In particular, the characteristics of the pressure sensors could be moderately controlled through a micro-patterned hole structure in the PUA spacer and size-designs of the patterned hole area. With the structural-tuning strategies, adequate control of the site-specific sensitivity in the range of 47~83 kPa−1 and in the sensing range from 0.1 to 20 kPa was achieved. Moreover, stacked AgNW/PUA/AgNW (APA) structural designed pressure sensors with mixed hole sizes of 10/200 µm and spacer thickness of 800 µm exhibited high sensitivity (~171.5 kPa−1) in the pressure sensing range of 0~20 kPa, fast response (100~110 ms), and high stretchability (40%). From the results, we envision that the effective structural-tuning strategy capable of controlling the sensing properties of the APA pressure sensor would be employed in a large-area stretchable pressure sensor system, which needs site-specific sensing properties, providing monolithic implementation by simply arranging appropriate micro-patterned hole architectures.


Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3465
Author(s):  
Jianli Cui ◽  
Xueli Nan ◽  
Guirong Shao ◽  
Huixia Sun

Researchers are showing an increasing interest in high-performance flexible pressure sensors owing to their potential uses in wearable electronics, bionic skin, and human–machine interactions, etc. However, the vast majority of these flexible pressure sensors require extensive nano-architectural design, which both complicates their manufacturing and is time-consuming. Thus, a low-cost technology which can be applied on a large scale is highly desirable for the manufacture of flexible pressure-sensitive materials that have a high sensitivity over a wide range of pressures. This work is based on the use of a three-dimensional elastic porous carbon nanotubes (CNTs) sponge as the conductive layer to fabricate a novel flexible piezoresistive sensor. The synthesis of a CNTs sponge was achieved by chemical vapor deposition, the basic underlying principle governing the sensing behavior of the CNTs sponge-based pressure sensor and was illustrated by employing in situ scanning electron microscopy. The CNTs sponge-based sensor has a quick response time of ~105 ms, a high sensitivity extending across a broad pressure range (less than 10 kPa for 809 kPa−1) and possesses an outstanding permanence over 4,000 cycles. Furthermore, a 16-pixel wireless sensor system was designed and a series of applications have been demonstrated. Its potential applications in the visualizing pressure distribution and an example of human–machine communication were also demonstrated.


2017 ◽  
Vol 13 (4) ◽  
pp. 581-583
Author(s):  
Muhammad Izuan ◽  
Raja Kamarulzaman Raja Ibrahim ◽  
Shabudin Bin Mat ◽  
Asrul Izam Bin Azmi

This work was done to investigate the feasibility of FBGs strain sensor in detection of air pressure on aeroplane model known as Generic UTM Half-Model. The FBGs was attached on the surface of  aeroplane model where its position is as near as possible to the location of static pressure sensor. Then, the sensing performance was tested inside UTM Low Speed Tunnel (UTM-LST) with the wind speed set at 30 , 40 , and 50 . The direction of wind was arranged to be in perpendicular to the sensing elements and the wing model angle was varied at 0°, 5°, 10°, 15°, and 20°. The measured pressure coefficient, Cp based on Bragg wavelength shift was compared with FKPS 30DP Pressure Measuring Module data. The results shows that the shift in Bragg wavelength found to be linearly increased when the wind speed is increased. The pressure coefficient obtained by FBG has approximate value as the pressure coefficient of pressure sensor module at low angle of attack from 0° to 12°.


2019 ◽  
Vol 13 (02) ◽  
pp. 2051002
Author(s):  
Shaowei Lu ◽  
Junchi Ma ◽  
Keming Ma ◽  
Shuai Wang ◽  
Xiangdong Yang ◽  
...  

High-performance pressure sensors have caused widespread concern due to the potential applications in 3D-touch technology and wearable electronic devices. Herein, a new type of graphene pressure sensor based on the glass fiber surfacing mat coated with graphene oxide aqueous solution by a spray-vacuum filtration method and HI acid reduction method is reported. It is a simple and highly effective method to reduce graphene oxide films into highly conductive graphene films without destroying their integrity and flexibility at a low temperature based on the nucleophilic substitution reaction. The FTIR, SEM and conductivity tests indicate that the optimum time for graphene oxide to be reduced is 30[Formula: see text]min, under this condition enter the epoxy group has been reacted without damaging the regular sp2 hybrid C atom structure in graphene. The conductivity of the graphene pressure sensor is increased significantly to 23260[Formula: see text]S/m. The monotonic compressing test for 100[Formula: see text]Pa/s and the test of the metal block placement and removal demonstrate that the sensor exhibits relatively high linearity of 99.74% between the response and pressure, the advantage makes the sensor monitor pressure more accurately. More importantly, the pressure sensor based on the glass fiber surfacing mat coated with graphene shows extremely high sensitivity (0.169[Formula: see text][Formula: see text]), fast response time (251[Formula: see text]ms) and good stability for 1000 cycles. Based on its superior performance, it also demonstrates potential applications in measuring pressure and human body’s motions.


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.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3895
Author(s):  
Yelin Ko ◽  
Chi Cuong Vu ◽  
Jooyong Kim

Flexible and wearable pressure sensors have attracted significant attention owing to their roles in healthcare monitoring and human–machine interfaces. In this study, we introduce a wide-range, highly sensitive, stable, reversible, and biocompatible pressure sensor based on a porous Ecoflex with tilted air-gap-structured and carbonized cotton fabric (CCF) electrodes. The knitted structure of electrodes demonstrated the effectiveness of the proposed sensor in enhancing the pressure-sensing performance in comparison to a woven structure due to the inherent properties of naturally generated space. In addition, the presence of tilted air gaps in the porous elastomer provided high deformability, thereby significantly improving the sensor sensitivity compared to other dielectric structures that have no or vertical air gaps. The combination of knitted CCF electrodes and the porous dielectric with tilted air gaps achieved a sensitivity of 24.5 × 10−3 kPa−1 at 100 kPa, along with a wide detection range (1 MPa). It is also noteworthy that this novel method is low-cost, facile, scalable, and ecofriendly. Finally, the proposed sensor integrated into a smart glove detected human motions of grasping water cups, thus demonstrating its potential applications in wearable electronics.


2020 ◽  
Author(s):  
Yunlu Lian ◽  
He Yu ◽  
Mingyuan Wang ◽  
Xiaonan Yang ◽  
Hefei Zhang

Abstract Flexible pressure sensors have attracted increasing attention due to their potential applications in wearable human health monitoring and care systems. Herein, we present a facile approach for fabricating all-textile-based piezoresistive pressure sensor with integrated Ag nanowire-coated fabrics. It fully takes advantage of the synergistic effect of the fiber/yarn/fabric multi-level contacts, leading to the ultrahigh sensitivity of 3.24×10 5 kPa −1 at 0–10 kPa and 2.16×10 4 kPa −1 at 10–100 kPa, respectively. Furthermore, the device achieved a fast response/relaxation time (32/24 ms), and a high stability (>1000 loading/unloading cycles). Thus, such all-textile pressure sensor with high performance is expected to be applicable in the fields of smart cloths, activity monitoring and healthcare device.


2021 ◽  
Vol 11 (19) ◽  
pp. 9012
Author(s):  
Mengru Jiao ◽  
Minghao Wang ◽  
Ye Fan ◽  
Bangbang Guo ◽  
Bowen Ji ◽  
...  

In this work, a MEMS piezoresistive micro pressure sensor (1.5 × 1.5 × 0.82 mm) is designed and fabricated with SOI-based micromachining technology and assembled using anodic bonding technology. In order to optimize the linearity and sensitivity over a wide effective pressure range (0–5 MPa) and temperature range (25–125 °C), the diaphragm thickness and the insulation of piezoresistors are precisely controlled by an optimized micromachining process. The consistency of the four piezoresistors is greatly improved by optimizing the structure of the ohmic contact pads. Furthermore, the probability of piezoresistive breakdown during anodic bonding is greatly reduced by conducting the top and bottom silicon of the SOI. At room temperature, the pressure sensor with 40 µm diaphragm demonstrates reliable linearity (0.48% F.S.) and sensitivity (33.04 mV/MPa) over a wide pressure range of 0–5.0 MPa. In addition, a polyimide protection layer is fabricated on the top surface of the sensor to prevent it from corrosion by a moist marine environment. To overcome the linearity drift due to temperature variation in practice, a digital temperature compensation system is developed for the pressure sensor, which shows a maximum error of 0.43% F.S. in a temperature range of 25–125 °C.


2020 ◽  
Author(s):  
Xiu Wang ◽  
Lu-Qi Tao ◽  
Min Yuan ◽  
Ze-Ping Wang ◽  
Jiabing Yu ◽  
...  

Abstract Sensitivity and pressure range are two significant parameters of pressure sensors. The existing pressure sensors are difficult to achieve both high sensitivity and a wide pressure range. In this regard, we proposed a new pressure sensor with a ternary nanocomposite Fe2O3/C@SnO2. Notably, the sea urchin-like Fe2O3 structure promoted signal transduction and protected Fe2O3 needles from mechanical breaking; while, acetylene carbon black improved the conductivity of Fe2O3. Moreover, one part of SnO2 nanoparticles adhered to the surface of Fe2O3 needles and formed Fe2O3/SnO2 heterostructures whereas its other part of nanoparticles dispersed into the carbon layer and formed SnO2@C structures. Collectively, the synergy of the three structures (Fe2O3/C, Fe2O3/SnO2 and SnO2@C) improved the limited pressure response range of a single structure. The experimental results demonstrated 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). This implies that the new pressure sensor has wide application prospects especially in wearable electronic devices and health monitoring.


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