scholarly journals Knitted strain sensor with carbon fiber and aluminum-coated yarn, for wearable electronics

2021 ◽  
Author(s):  
Junhyeok Jang ◽  
Suji Kim ◽  
Kangmin Lee ◽  
Seungjun Park ◽  
Geum-Yong Park ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Type Strain ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Motion Sensor ◽  
Wearable Electronics ◽  
Higher Sensitivity

A knitted textile-type strain sensor with RRAM characteristics is developed. We demonstrated that the developed sensor has a higher sensitivity than previously demonstrated textile strain sensors and can be used as a motion sensor by applying it to clothes.

scholarly journals A novel strain sensor using a microchannel embedded in PDMS

2018 ◽  
Vol 4 (2) ◽  
pp. 1 ◽  
Author(s):  
Angelica Campigotto ◽  
Stephane Leahy ◽  
Ayan Choudhury ◽  
Guowei Zhao ◽  
Yongjun Lai
Keyword(s):  
Finite Element ◽  
Rotation Angle ◽  
Strain Sensor ◽  
Element Model ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Sectional Area ◽  
Cross Sectional ◽  
Higher Sensitivity

A novel, inexpensive, and easy-to-use strain sensor using polydimethylsiloxane (PDMS)  was developed. The sensor consists of a microchannel that is partially filled with a coloured liquid and embedded in a piece of PDMS. A finite element model was developed to optimize the geometry of the microchannel to achieve higher sensitivity. The highest gauge factor that was measured experimentally was 41. The gauge factor was affected by the microchannel’s square cross-sectional area, the number of basic units in the microchannel, and the inlet and outlet configuration. As a case study, the developed strain sensors were used to measure the rotation angle of the wrist and finger joints.

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 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 Highly sensitive strain sensors based on hollow packaged silver nanoparticle-decorated three-dimensional graphene foams for wearable electronics

RSC Advances ◽  
2019 ◽  
Vol 9 (68) ◽  
pp. 39958-39964
Author(s):  
Xinxiu Wu ◽  
Fangfang Niu ◽  
Ao Zhong ◽  
Fei Han ◽  
Yun Chen ◽  
...  
Keyword(s):  
Silver Nanoparticle ◽  
Three Dimensional ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Strain Sensors ◽  
Sensitive Strain ◽  
Wearable Electronics ◽  
Sensor Applications ◽  
Highly Sensitive ◽  
Graphene Foams

Silver nanoparticle-decorated three-dimensional graphene foams were prepared and packaged with half-cured PMDS films, forming a special “hollow packaged” structure that exhibited high sensitivity for wearable strain sensor applications.

Highly Stretchable Resistive Strain Sensors Using Multiple Viscous Conductive Materials

2020 ◽  
Author(s):  
Hongyang Shi ◽  
Xinda Qi ◽  
Yunqi Cao ◽  
Nelson Sepúlveda ◽  
Chuan Wang ◽  
...  
Keyword(s):  
Large Strain ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Fabrication Process ◽  
Gauge Factor ◽  
Wearable Electronics ◽  
Detection Range ◽  
Conductive Materials ◽  
Highly Stretchable ◽  
Good Repeatability

Abstract This paper proposes a highly stretchable strain sensor using viscous conductive materials as resistive element and introduces a simple and economic fabrication process by encapsulating the conductive materials between two layers of silicone rubbers Ecoflex 00-30. The fabrication process of the strain sensor is presented, and the properties of the viscous conductive materials are studied. Characterization shows that the sensor with conductive gels, toothpastes, carbon paint, and carbon grease can sustain a maximum tensile strain of 200% and retain good repeatability, with a strain gauge factor of 2.0, 1.75, 3.0, and 7.5, respectively. Furthermore, strain sensors with graphite and carbon nanotubes mixed with conductive gels are fabricated to explore how to improve the gauge factor. With a focus on the most promising material, conductive carbon grease, cyclic stretching tests are conducted and show good repeatability at 100% strain for 100 cycles. Lastly, it is demonstrated that the stretchable strain sensor made of carbon grease is capable of measuring finger bending. With its easy and low-cost fabrication process, large strain detection range and good gauge factor, the conductive materials-based strain sensors are promising for future biomedical, wearable electronics and rehabilitation applications.

scholarly journals Development of Highly Sensitive Strain Sensor Using Area-Arrayed Graphene Nanoribbons

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1701
Author(s):  
Ken Suzuki ◽  
Ryohei Nakagawa ◽  
Qinqiang Zhang ◽  
Hideo Miura
Keyword(s):  
Graphene Nanoribbons ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Sensitive Strain ◽  
Bending Test ◽  
Gauge Factor ◽  
Four Point Bending ◽  
Current Voltage ◽  
Highly Sensitive ◽  
Current Voltage Relationship

In this study, a basic design of area-arrayed graphene nanoribbon (GNR) strain sensors was proposed to realize the next generation of strain sensors. To fabricate the area-arrayed GNRs, a top-down approach was employed, in which GNRs were cut out from a large graphene sheet using an electron beam lithography technique. GNRs with widths of 400 nm, 300 nm, 200 nm, and 50 nm were fabricated, and their current-voltage characteristics were evaluated. The current values of GNRs with widths of 200 nm and above increased linearly with increasing applied voltage, indicating that these GNRs were metallic conductors and a good ohmic junction was formed between graphene and the electrode. There were two types of GNRs with a width of 50 nm, one with a linear current–voltage relationship and the other with a nonlinear one. We evaluated the strain sensitivity of the 50 nm GNR exhibiting metallic conduction by applying a four-point bending test, and found that the gauge factor of this GNR was about 50. Thus, GNRs with a width of about 50 nm can be used to realize a highly sensitive strain sensor.

scholarly journals Strain Sensor Based on Biological Nanomaterial

2021 ◽  
Vol 6 (1) ◽  
pp. 23
Author(s):  
Levan P. Ichkitidze ◽  
Alexander Yu. Gerasimenko ◽  
Dmitry V. Telyshev ◽  
Eugeny P. Kitsyuk ◽  
Vladimir A. Petukhov ◽  
...  
Keyword(s):  
Screen Printing ◽  
Respiratory Diseases ◽  
Specific Conductivity ◽  
Strain Sensor ◽  
Aqueous Dispersion ◽  
Strain Sensors ◽  
Bending Angle ◽  
Multi Walled Carbon Nanotubes ◽  
Number Of Cycles ◽  
Walled Carbon Nanotubes

We investigated a prototype of a strain sensor based on the layers of a bionanomaterial containing bovine serum albumin (BSA matrix) and multi-walled carbon nanotubes (MWCNT filler). The aqueous dispersion of 25 wt.% BSA/0.3 wt.% MWCNT was applied by screen printing onto flexible polyethylene terephthalate substrates. After drying the layers by laser irradiation (~970 nm), various parameters of the layers were controlled, i.e., resistance R, bending angle θ, number of cycles n, and measurement time. One measurement cycle corresponded to a change within the range θ = ±150°. The layers of the BSA/MWCNT bionanomaterial had dimensions of (15 ÷ 20) mm × (8 ÷ 10) mm × (0.5 ÷ 1. 5) µm. The dependences of resistance R on the bending angle θ were similar for all layers at θ = ±30, and the R(θ) curves represented approximate linear dependences (with an error of ≤ 10%); beyond this range, the dependences became nonlinear. The following quantitative values were obtained for the investigated strain sensor: specific conductivity ~1 ÷ 10 S/m, linear strain sensitivity ~160, and bending sensitivity 1.0 ÷ 1.5%/°. These results are high. The examined layers of the bionanomaterial BSA/MWCNT as a strain sensor are of particular interest for medical practice. In particular, strain sensors can be implemented by applying a water dispersion of nanomaterials to human skin using a 3D printer for monitoring movements (arms and blinking) and the detection of signs of pathology (dysphagia, respiratory diseases, angina, etc.).

scholarly journals Anisotropic, Wrinkled, and Crack-Bridging Structure for Ultrasensitive, Highly Selective Multidirectional Strain Sensors

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Heng Zhang ◽  
Dan Liu ◽  
Jeng-Hun Lee ◽  
Haomin Chen ◽  
Eunyoung Kim ◽  
...  
Keyword(s):  
Rational Design ◽  
Full Range ◽  
Human Motion ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Wearable Electronics ◽  
Trade Off ◽  
Human Motion Detection ◽  
Sensing Applications ◽  
Anisotropic Structures

AbstractFlexible multidirectional strain sensors are crucial to accurately determining the complex strain states involved in emerging sensing applications. Although considerable efforts have been made to construct anisotropic structures for improved selective sensing capabilities, existing anisotropic sensors suffer from a trade-off between high sensitivity and high stretchability with acceptable linearity. Here, an ultrasensitive, highly selective multidirectional sensor is developed by rational design of functionally different anisotropic layers. The bilayer sensor consists of an aligned carbon nanotube (CNT) array assembled on top of a periodically wrinkled and cracked CNT–graphene oxide film. The transversely aligned CNT layer bridge the underlying longitudinal microcracks to effectively discourage their propagation even when highly stretched, leading to superior sensitivity with a gauge factor of 287.6 across a broad linear working range of up to 100% strain. The wrinkles generated through a pre-straining/releasing routine in the direction transverse to CNT alignment is responsible for exceptional selectivity of 6.3, to the benefit of accurate detection of loading directions by the multidirectional sensor. This work proposes a unique approach to leveraging the inherent merits of two cross-influential anisotropic structures to resolve the trade-off among sensitivity, selectivity, and stretchability, demonstrating promising applications in full-range, multi-axis human motion detection for wearable electronics and smart robotics.

scholarly journals A Novel Textile Stitch-Based Strain Sensor for Wearable End Users

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1469 ◽  
Author(s):  
Orathai Tangsirinaruenart ◽  
George Stylios
Keyword(s):  
Mechanical Properties ◽  
Electrical Resistance ◽  
Body Movement ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Heart Monitoring ◽  
Textile Sensors ◽  
Good Repeatability ◽  
The Ideal

This research presents an investigation of novel textile-based strain sensors and evaluates their performance. The electrical resistance and mechanical properties of seven different textile sensors were measured. The sensors are made up of a conductive thread, composed of silver plated nylon 117/17 2-ply, 33 tex and 234/34 4-ply, 92 tex and formed in different stitch structures (304, 406, 506, 605), and sewn directly onto a knit fabric substrate (4.44 tex/2 ply, with 2.22, 4.44 and 7.78 tex spandex and 7.78 tex/2 ply, with 2.22 and 4.44 tex spandex). Analysis of the effects of elongation with respect to resistance indicated the ideal configuration for electrical properties, especially electrical sensitivity and repeatability. The optimum linear working range of the sensor with minimal hysteresis was found, and the sensor’s gauge factor indicated that the sensitivity of the sensor varied significantly with repeating cycles. The electrical resistance of the various stitch structures changed significantly, while the amount of drift remained negligible. Stitch 304 2-ply was found to be the most suitable for strain movement. This sensor has a wide working range, well past 50%, and linearity (R2 is 0.984), low hysteresis (6.25% ΔR), good gauge factor (1.61), and baseline resistance (125 Ω), as well as good repeatability (drift in R2 is −0.0073). The stitch-based sensor developed in this research is expected to find applications in garments as wearables for physiological wellbeing monitoring such as body movement, heart monitoring, and limb articulation measurement.

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