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

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1077 ◽  
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.

scholarly journals Polymer-Based Self-Standing Flexible Strain Sensor

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Fernando Martinez ◽  
Gregorio Obieta ◽  
Ion Uribe ◽  
Tomasz Sikora ◽  
Estibalitz Ochoteco
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistance ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Wearable Electronics ◽  
Rehabilitation Devices ◽  
Flexible Strain Sensor

The design and characterization of polymer-based self-standing flexible strain sensors are presented in this work. Properties as lightness and flexibility make them suitable for the measurement of strain in applications related with wearable electronics such as robotics or rehabilitation devices. Several sensors have been fabricated to analyze the influence of size and electrical conductivity on their behavior. Elongation and applied charge were precisely controlled in order to measure different parameters as electrical resistance, gauge factor (GF), hysteresis, and repeatability. The results clearly show the influence of size and electrical conductivity on the gauge factor, but it is also important to point out the necessity of controlling the hysteresis and repeatability of the response for precision-demanding applications.

scholarly journals A Pressure-Insensitive Self-Attachable Flexible Strain Sensor with Bioinspired Adhesive and Active CNT Layers

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6965
Author(s):  
Minho Seong ◽  
Insol Hwang ◽  
Joosung Lee ◽  
Hoon Eui Jeong
Keyword(s):  
Tensile Strain ◽  
High Strain ◽  
Strain Sensor ◽  
Adhesive Layer ◽  
High Sensitivity ◽  
Gauge Factor ◽  
Tactile Sensors ◽  
Surface Attachment ◽  
Tactile Stimuli ◽  
Flexible Strain Sensor

Flexible tactile sensors are required to maintain conformal contact with target objects and to differentiate different tactile stimuli such as strain and pressure to achieve high sensing performance. However, many existing tactile sensors do not have the ability to distinguish strain from pressure. Moreover, because they lack intrinsic adhesion capability, they require additional adhesive tapes for surface attachment. Herein, we present a self-attachable, pressure-insensitive strain sensor that can firmly adhere to target objects and selectively perceive tensile strain with high sensitivity. The proposed strain sensor is mainly composed of a bioinspired micropillar adhesive layer and a selectively coated active carbon nanotube (CNT) layer. We show that the bioinspired adhesive layer enables strong self-attachment of the sensor to diverse planar and nonplanar surfaces with a maximum adhesion strength of 257 kPa, while the thin film configuration of the patterned CNT layer enables high strain sensitivity (gauge factor (GF) of 2.26) and pressure insensitivity.

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

Nanoscale ◽  
2018 ◽  
Vol 10 (28) ◽  
pp. 13599-13606 ◽  
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%).

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

Nanomaterials ◽  
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.

scholarly journals Cost-Effective Fabrication of Transparent Strain Sensors via Micro-Scale 3D Printing and Imprinting

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 120
Author(s):  
Rui Wang ◽  
Xiaoyang Zhu ◽  
Luanfa Sun ◽  
Shuai Shang ◽  
Hongke Li ◽  
...  
Keyword(s):  
3D Printing ◽  
Health Monitoring ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Wearable Devices ◽  
Strain Sensors ◽  
Expression Recognition ◽  
Wrist Flexion ◽  
Multiwalled Carbon ◽  
Flexible Strain Sensor

The development of strain sensors with high sensitivity and stretchability is essential for health monitoring, electronic skin, wearable devices, and human-computer interactions. However, sensors that combine high sensitivity and ultra-wide detection generally require complex preparation processes. Here, a novel flexible strain sensor with high sensitivity and transparency was proposed by filling a multiwalled carbon nanotube (MWCNT) solution into polydimethylsiloxane (PDMS) channel films fabricated via an electric field-driven (EFD) 3D printing and molding hybrid process. The fabricated flexible strain sensor with embedded MWCNT networks had superior gauge factors of 90, 285, and 1500 at strains of 6.6%, 14%, and 20%, respectively. In addition, the flexible strain sensors with an optical transparency of 84% offered good stability and durability with no significant change in resistance after 8000 stretch-release cycles. Finally, the fabricated flexible strain sensors with embedded MWCNT networks showed good practical performance and could be attached to the skin to monitor various human movements such as wrist flexion, finger flexion, neck flexion, blinking activity, food swallowing, and facial expression recognition. These are good application strategies for wearable devices and health monitoring.

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

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.

scholarly journals Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

2020 ◽  
Vol 11 ◽  
pp. 1847-1853
Author(s):  
Jianqi Dong ◽  
Liang Chen ◽  
Yuqing Yang ◽  
Xingfu Wang
Keyword(s):  
Integrated Circuits ◽  
Indium Tin Oxide ◽  
Quantum Confinement Effect ◽  
Strain Sensor ◽  
Volume Ratio ◽  
High Sensitivity ◽  
Gauge Factor ◽  
Oxide Electrodes ◽  
Poly Ethylene ◽  
Flexible Strain Sensor

1D semiconductor nanowires (NWs) have been extensively studied in recent years due to the predominant mechanical flexibility caused by a large surface-to-volume ratio and unique electrical and optical properties induced by the 1D quantum confinement effect. Herein, we use a top-down two-step preparation method to synthesize AlGaN/AlN/GaN heterojunction NWs with controllable size. A single NW is transferred to a flexible poly(ethylene terephthalate) substrate and fixed by indium tin oxide electrodes to form an ohmic contact for the strain sensor. An external mechanical stress is introduced to study the performance of the fabricated piezotronic strain sensor. The gauge factor is as high as 30 under compressive or tensile stress, which indicates a high sensitivity of the strain sensor. Periodic strain tests show the high stability and repeatability of the sensor. The working mechanism of the strain sensor is investigated and systematically analyzed under compressive and tensile strain. Here, we describe a strain sensor that shows a great application potential in wearable integrated circuits, in health-monitoring devices, and in artificial intelligence.

Flexible strain sensor with high sensitivity, fast response, and good sensing range for wearable applications

2021 ◽  
Author(s):  
Suresh Nuthalapati ◽  
Vaishakh Kedambaimoole ◽  
Vijay Shirhatti ◽  
Saurabh Kumar ◽  
Hidekuni Takao ◽  
...  
Keyword(s):  
Strain Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Sensing Range ◽  
Flexible Strain Sensor

Ti3C2Tx MXene/polyvinyl alcohol decorated polyester warp knitting fabric for flexible wearable strain sensors

2021 ◽  
pp. 004051752110441
Author(s):  
Qinghua Yu ◽  
Jinhua Jiang ◽  
Chuanli Su ◽  
Yaoli Huang ◽  
Nanliang Chen ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Self Assembly ◽  
Low Cost ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Disease Diagnosis ◽  
Strain Sensors ◽  
Layer By Layer ◽  
Sensing Range

Flexible wearable strain sensors with excellent sensing performance have received widespread interest due to their superior application capability in the field of human-computer interaction, sports rehabilitation, and disease diagnosis. But at present, it is still a considerable challenge to exploit a flexible strain sensor with high sensitivity and wide sensing range that is easily manufactured, low-cost, and easily integrable into clothing. MXene is a promising material sensitive enough for flexible sensors due to its superior conductivity and hydrophilicity. The warp knitting weft insertion textile structure gives the fabric excellent elasticity, making it suitable as a flexible, stretchable substrate. Therefore, utilizing a polyester elastic fabric with a warp knitting weft insertion structure, a fabric strain sensor with high sensitivity and wide sensing range prepared by layer-by-layer self-assembly of polyvinyl alcohol layers and MXene layers is reported in this study. The strain sensor exhibits high sensitivity (up to 288.43), a wide sensing range (up to 50%), fast response time (50 ms), ultra-low detection limit (a strain of 0.067%), excellent cycle stability (1000 cycles), and good washability. Besides, affixing the MXene/polyvinyl alcohol/polyester elastic fabric strain sensor on the joints can detect the movement of limbs. Therefore, the MXene/polyvinyl alcohol/polyester elastic fabric strain sensor demonstrates potential application opportunities in smart wearable electronic devices, and the researcher can also apply this method in the production of other flexible, intelligent wearable devices.

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

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2834 ◽  
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.

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