Giant gauge factor of Van der Waals material based strain sensors

AbstractThere is an emergent demand for high-flexibility, high-sensitivity and low-power strain gauges capable of sensing small deformations and vibrations in extreme conditions. Enhancing the gauge factor remains one of the greatest challenges for strain sensors. This is typically limited to below 300 and set when the sensor is fabricated. We report a strategy to tune and enhance the gauge factor of strain sensors based on Van der Waals materials by tuning the carrier mobility and concentration through an interplay of piezoelectric and photoelectric effects. For a SnS2 sensor we report a gauge factor up to 3933, and the ability to tune it over a large range, from 23 to 3933. Results from SnS2, GaSe, GeSe, monolayer WSe2, and monolayer MoSe2 sensors suggest that this is a universal phenomenon for Van der Waals semiconductors. We also provide proof of concept demonstrations by detecting vibrations caused by sound and capturing body movements.

Download Full-text

Ti3C2Tx MXene-graphene composite films for wearable strain sensors featured with high sensitivity and large range of linear response

Nano Energy ◽

10.1016/j.nanoen.2019.104134 ◽

2019 ◽

Vol 66 ◽

pp. 104134 ◽

Cited By ~ 17

Author(s):

Yina Yang ◽

Zherui Cao ◽

Peng He ◽

Liangjing Shi ◽

Guqiao Ding ◽

...

Keyword(s):

Linear Response ◽

Large Range ◽

Composite Films ◽

High Sensitivity ◽

Strain Sensors ◽

Graphene Composite

Download Full-text

Controllable Fabrication of Percolative Metal Nanoparticle Arrays Applied for Quantum Conductance-Based Strain Sensors

Materials ◽

10.3390/ma13214838 ◽

2020 ◽

Vol 13 (21) ◽

pp. 4838

Author(s):

Zhengyang Du ◽

Ji’an Chen ◽

Chang Liu ◽

Chen Jin ◽

Min Han

Keyword(s):

Electron Tunneling ◽

Electrical Conductance ◽

High Sensitivity ◽

Strain Sensors ◽

Metal Nanoparticle ◽

Gauge Factor ◽

Electron Conduction ◽

Percolation Clusters ◽

Interdigital Electrodes ◽

Controllable Fabrication

We use gas phase deposition of well-defined nanoparticles (NPs) to fabricate closely-spaced Pd NP arrays on flexible membranes prepatterned with interdigital electrodes (IDEs). The evolution of the morphology and electron conductance of the NP arrays during deposition is analyzed. The growth of two-dimensional percolation clusters of interconnected NPs, which correlate with the percolation pathway for electron conduction in the NP deposits, is demonstrated. The percolative nature of the NP arrays permits us to finely control the percolation geometries and conductance of the NP film by controlling the NP deposition time so as to realize a precise and reproducible fabrication of sensing materials. Electron transport measurements reveal that the electrical conductance of the NP films is dominated by electron tunneling or hopping across the NP percolating networks. Based on the percolative and quantum tunneling nature, the closely-spaced Pd NP films on PET membranes are used as flexible strain sensors. The sensor demonstrates an excellent response ability to distinguish tiny deformations down to 5×10−4 strain and a high sensitivity with a large gauge factor of 200 up to 4% applied strain.

Download Full-text

Calibration of piezoresistive shape-memory alloy strain sensors

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x211057206 ◽

2021 ◽

pp. 1045389X2110572

Author(s):

Thomas Mäder ◽

Jonas v Heusinger ◽

Björn Senf ◽

Martin Zoch ◽

Anja Winkler ◽

...

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Glass Fibre ◽

Strain Sensors ◽

Strain Gauges ◽

Gauge Factor ◽

Standard Strain ◽

Four Point Bending ◽

Glass Fibre Reinforced ◽

Mechanical Sensors

Continuous strain measurement on fibre-reinforced structures demands mechanical sensors with superior fatigue resistance. Shape-memory alloy wires are predestined for strain sensors utilising their strong piezo-resistance. Calibration of these sensors is necessary in order to extract mechanical data. Therefore, four-point bending of glass-fibre reinforced plastic specimens with applied strain sensors and an optical reference measuring system is used to calibrate and compare shape-memory alloy sensors and standard strain gauges. The gauge factor and its standard deviation is successfully measured by this calibration method. Shape-memory alloy sensors show strain-dependent gauge factor whilst standard strain gauges show a constant strain sensitivity, both with a narrow stochastic distribution. Shape-memory alloy mechanical sensors are reliable to determine strain of fibre-reinforced structures. This offers the possibility to use them in structural health monitoring applications of such structures. Consequently, the four-point bending calibration using glass-fibre reinforced specimens represents a suitable possibility for calibration of strain sensors exposed to higher strain amplitudes.

Download Full-text

Flexible and Highly Sensitive Strain Sensor Based on Laser-Induced Graphene Pattern Fabricated by 355 nm Pulsed Laser

Sensors ◽

10.3390/s19224867 ◽

2019 ◽

Vol 19 (22) ◽

pp. 4867 ◽

Cited By ~ 5

Author(s):

Sung-Yeob Jeong ◽

Yong-Won MA ◽

Jun-Uk Lee ◽

Gyeong-Ju Je ◽

Bo-sung Shin

Keyword(s):

Focal Length ◽

Pulsed Laser ◽

Strain Sensor ◽

High Sensitivity ◽

Gauge Factor ◽

Functional Evaluation ◽

Mechanical Fracture ◽

Highly Sensitive ◽

Human Finger ◽

Small Deformations

A laser-induced-graphene (LIG) pattern fabricated using a 355 nm pulsed laser was applied to a strain sensor. Structural analysis and functional evaluation of the LIG strain sensor were performed by Raman spectroscopy, scanning electron microscopy (SEM) imaging, and electrical–mechanical coupled testing. The electrical characteristics of the sensor with respect to laser fluence and focal length were evaluated. The sensor responded sensitively to small deformations, had a high gauge factor of ~160, and underwent mechanical fracture at 30% tensile strain. In addition, we have applied the LIG sensor, which has high sensitivity, a simple manufacturing process, and good durability, to human finger motion monitoring.

Download Full-text

Highly sensitive and stretchable strain sensors based on chopped carbon fibers sandwiched between silicone rubber layers for human motion detections

Journal of Composite Materials ◽

10.1177/0021998319855758 ◽

2019 ◽

Vol 54 (3) ◽

pp. 423-434 ◽

Cited By ~ 4

Author(s):

MB Azizkhani ◽

Sh Rastgordani ◽

A. Pourkamali Anaraki ◽

J Kadkhodapour ◽

B Shirkavand Hadavand

Keyword(s):

Carbon Fibers ◽

Motion Detection ◽

Silicone Rubber ◽

Low Cost ◽

High Sensitivity ◽

Human Motion ◽

Strain Sensors ◽

Body Motion ◽

Gauge Factor ◽

Human Motion Detection

Tuning the electromechanical performance in piezoresistive composite strain sensors is primarily attained through appropriately employing the materials system and the fabrication process. High sensitivity along with flexibility in the strain sensing devices needs to be met according to the application (e.g. human motion detection, health and sports monitoring). In this paper, a highly stretchable and sensitive strain sensor with a low-cost fabrication is proposed which is acquired by embedding the chopped carbon fibers sandwiched in between silicone rubber layers. The electrical and mechanical features of the sensor were characterized through stretch/release loading tests where a considerably high sensitivity (the gauge factor about 100) was observed with very low hysteresis. This implies high strain reversibility (i.e. full recovery in each cycle) over 700 loading cycles. Moreover, the sensors exhibited ultra-high stretchability (up to ∼300% elongation) in addition to a low stiffness meaning minimal mechanical effects induced by the sensor for sensitive human motion monitoring applications including large and small deformations. The results suggest the promising capability of the present sensor in reflecting the human body motion detection.

Download Full-text

Ultra-stretchable and highly sensitive strain sensor based on gradient structure carbon nanotubes

Nanoscale ◽

10.1039/c8nr02528b ◽

2018 ◽

Vol 10 (28) ◽

pp. 13599-13606 ◽

Cited By ~ 31

Author(s):

Binghao Liang ◽

Zhiqiang Lin ◽

Wenjun Chen ◽

Zhongfu He ◽

Jing Zhong ◽

...

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Strain Sensor ◽

High Sensitivity ◽

Strain Sensors ◽

Sensitive Strain ◽

Gauge Factor ◽

Gradient Structure ◽

Highly Sensitive ◽

Highly Stretchable

A highly stretchable and sensitive strain sensor based on a gradient carbon nanotube was developed. The strain sensors show an unprecedented combination of both high sensitivity (gauge factor = 13.5) and ultra-stretchability (>550%).

Download Full-text

Highly Sensitive and Stretchable c-MWCNTs/PPy Embedded Multidirectional Strain Sensor Based on Double Elastic Fabric for Human Motion Detection

Nanomaterials ◽

10.3390/nano11092333 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2333

Author(s):

Huiying Shen ◽

Huizhen Ke ◽

Jingdong Feng ◽

Chenyu Jiang ◽

Qufu Wei ◽

...

Keyword(s):

Degrees Of Freedom ◽

Large Scale ◽

Strain Sensor ◽

High Sensitivity ◽

Human Motion ◽

Strain Sensors ◽

Gauge Factor ◽

Wearable Electronics ◽

Synovial Joint ◽

Human Motion Detection

Owing to the multi-dimensional complexity of human motions, traditional uniaxial strain sensors lack the accuracy in monitoring dynamic body motions working in different directions, thus multidirectional strain sensors with excellent electromechanical performance are urgently in need. Towards this goal, in this work, a stretchable biaxial strain sensor based on double elastic fabric (DEF) was developed by incorporating carboxylic multi-walled carbon nanotubes(c-MWCNTs) and polypyrrole (PPy) into fabric through simple, scalable soaking and adsorption-oxidizing methods. The fabricated DEF/c-MWCNTs/PPy strain sensor exhibited outstanding anisotropic strain sensing performance, including relatively high sensitivity with the maximum gauge factor (GF) of 5.2, good stretchability of over 80%, fast response time < 100 ms, favorable electromechanical stability, and durability for over 800 stretching–releasing cycles. Moreover, applications of DEF/c-MWCNTs/PPy strain sensor for wearable devices were also reported, which were used for detecting human subtle motions and dynamic large-scale motions. The unconventional applications of DEF/c-MWCNTs/PPy strain sensor were also demonstrated by monitoring complex multi-degrees-of-freedom synovial joint motions of human body, such as neck and shoulder movements, suggesting that such materials showed a great potential to be applied in wearable electronics and personal healthcare monitoring.

Download Full-text

High-Performance Wearable Strain Sensor Based on MXene@Cotton Fabric with Network Structure

10.21203/rs.3.rs-184921/v1 ◽

2021 ◽

Author(s):

Lu Liu ◽

Libo Wang ◽

Xuqing Liu ◽

Wenfeng Yuan ◽

Mengmeng Yuan ◽

...

Keyword(s):

Cotton Fabric ◽

High Performance ◽

Mechanical Performance ◽

Active Material ◽

Large Body ◽

Strain Sensor ◽

Strain Range ◽

High Sensitivity ◽

Strain Sensors ◽

Gauge Factor

Abstract Although 2D nanomaterials such as MXene Ti3C2Tx have been used in flexible electronic devices for their unique properties such as high conductivity, excellent mechanical performance, flexibility, and good hydrophilicity, less research has focused on of MXene-based cotton fabric strain sensors. Moreover, fabrication of wearable strain sensors with a low cost, high sensitivity, good biocompatibility, and broad sensing range is still a challenge. In this work, a high-performance wearable strain sensor composed of 2D MXene d-Ti3C2Tx nanomaterials and cotton fabric is reported. As the active material in the sensor, MXene d-Ti3C2Tx exhibited an excellent conductivity and hydrophilicity and adhered well to the fabric fibers by electrostatic adsorption. Due to the unique structure of the fabric substrate and the properties of MXene sheets, the fabricated pressure sensor achieved a high sensitivity. The gauge factor of the MXene@cotton fabric strain sensor reached up to 4.11 within the strain range of 15 %. Meanwhile, the sensor possessed high durability (>500 cycles) and a low strain detection limit of 0.3%. Finally, the encapsulated strain sensor was used to detect subtle or large body movements and exhibited a rapid response. This study shows that the MXene@cotton fabric strain sensor reported here have great potential for use in flexible, comfortable, and wearable devices for health monitoring and motion detection.

Download Full-text

Nano-Cracked Strain Sensor with High Sensitivity and Linearity by Controlling the Crack Arrangement

Sensors ◽

10.3390/s19122834 ◽

2019 ◽

Vol 19 (12) ◽

pp. 2834 ◽

Cited By ~ 5

Author(s):

Hyunsuk Jung ◽

Chan Park ◽

Hyunwoo Lee ◽

Seonguk Hong ◽

Hyonguk Kim ◽

...

Keyword(s):

Pulse Wave ◽

Wearable Sensors ◽

Strain Sensor ◽

Strain Range ◽

High Sensitivity ◽

Strain Sensors ◽

Gauge Factor ◽

Micro Deformation ◽

Sensing Performance ◽

Limited Sensitivity

Studies on wearable sensors that monitor various movements by attaching them to a body have received considerable attention. Crack-based strain sensors are more sensitive than other sensors. Owing to their high sensitivity, these sensors have been investigated for measuring minute deformations occurring on the skin, such as pulse. However, existing studies have limited sensitivity at low strain range and nonlinearity that renders any calibration process complex and difficult. In this study, we propose a pre-strain and sensor-extending process to improve the sensitivity and linearity of the sensor. By using these pre-strain and sensor-extending processes, we were able to control the morphology and alignment of cracks and regulate the sensitivity and linearity of the sensor. Even if the sensor was fabricated in the same manner, the sensor that involved the pre-strain and extending processes had a sensitivity 100 times greater than normal sensors. Thus, our crack-based strain sensor had high sensitivity (gauge factor > 5000, gauge factor (GF = (△R/R0)/ε), linearity, and low hysteresis at low strain (<1% strain). Given its high sensing performance, the sensor can be used to measure micro-deformation, such as pulse wave and voice.

Download Full-text

A Sprayed Graphene Pattern-Based Flexible Strain Sensor with High Sensitivity and Fast Response

Sensors ◽

10.3390/s19051077 ◽

2019 ◽

Vol 19 (5) ◽

pp. 1077 ◽

Cited By ~ 5

Author(s):

Wei Xu ◽

Tingting Yang ◽

Feng Qin ◽

Dongdong Gong ◽

Yijia Du ◽

...

Keyword(s):

Strain Sensor ◽

High Sensitivity ◽

Fast Response ◽

Strain Sensors ◽

Biomedical Science ◽

Gauge Factor ◽

Experimental Conditions ◽

Simple Method ◽

Wide Range ◽

Flexible Strain Sensor

Flexible strain sensors have a wide range of applications in biomedical science, aerospace industry, portable devices, precise manufacturing, etc. However, the manufacturing processes of most flexible strain sensors previously reported have usually required high manufacturing costs and harsh experimental conditions. Besides, research interests are often focused on improving a single attribute parameter while ignoring others. This work aims to propose a simple method of manufacturing flexible graphene-based strain sensors with high sensitivity and fast response. Firstly, oxygen plasma treats the substrate to improve the interfacial interaction between graphene and the substrate, thereby improving device performance. The graphene solution is then sprayed using a soft PET mask to define a pattern for making the sensitive layer. This flexible strain sensor exhibits high sensitivity (gauge factor ~100 at 1% strain), fast response (response time: 400–700 μs), good stability (1000 cycles), and low overshoot (<5%) as well. Those processes used are compatible with a variety of complexly curved substrates and is expected to broaden the application of flexible strain sensors.

Download Full-text