Hierarchical Porous Carbon-Nanotube Skeleton for Sensing Film with Ultrahigh Sensitivity, Stretchability, and Mechanical Compliance

2021 ◽  
Author(s):  
Xiao Han ◽  
Hongbo Zhang ◽  
Wei Xiao ◽  
Xiaolong Han ◽  
Aihua He ◽  
...  
Keyword(s):  
Thin Film ◽  
Health Monitoring ◽  
High Sensitivity ◽  
Strain Sensors ◽  
Hierarchical Porous Carbon ◽  
Minimal Invasiveness ◽  
Mechanical Compliance ◽  
Hierarchical Porous ◽  
Ultrahigh Sensitivity ◽  
Potential Use

Thin-film wearable strain sensors attract increasing attention due to their minimal invasiveness onto the human skin and potential use in health monitoring; however, the simultaneous achievement of high sensitivity and...

Area-Arrayed Graphene Nano-Ribbon-Base Strain Sensor

2018 ◽  
Author(s):  
Ryohei Nakagawa ◽  
Zhi Wang ◽  
Ken Suzuki
Keyword(s):  
Chemical Vapor Deposition ◽  
Stress Concentration ◽  
Health Monitoring ◽  
Vapor Deposition ◽  
Strain Sensor ◽  
Chemical Vapor ◽  
High Sensitivity ◽  
Strain Sensors ◽  
Chemical Vapor Deposition Method ◽  
High Quality

Health monitoring devices using a strain sensor, which shows high sensitivity and large deformability, are strongly demanded due to further aging of society with fewer children. Conventional strain sensors, such as metallic strain gauges and semiconductive strain sensors, however, aren’t applicable to health monitoring because of their low sensitivity and deformability. In this study, fundamental design of area-arrayed graphene nano-ribbon (GNR) strain senor was proposed in order to fabricate next-generation strain sensor. The sensor was consisted of two sections, which are stress concentration section and stress detecting section. This structure can take full advantage of GNR’s properties. Moreover, high quality GNR fabrication process, which is one of the important process in the sensor, was developed by applying CVD (Chemical Vapor Deposition) method. Top-down approach was applied to fabricate the GNR. At first, in order to synthesize a high-quality graphene sheet, acetylene-based LPCVD (low pressure chemical vapor deposition) using a closed Cu foil was employed. After that, graphene was transferred silicon substrate and the quality was evaluated. The high quality graphene was transferred on the soft PDMS substrate and metallic electrodes were fabricated by applying MEMS technology. Area-arrayed fine pin structure was fabricated by using hard PDMS as a stress-concentration section. Finally, both sections were integrated to form a highly sensitive and large deformable pressure sensor. The strain sensitivity of the GNR-base sensor was also evaluated.

Ultrasensitive micro/nanocrack-based graphene nanowall strain sensors derived from the substrate's Poisson's ratio effect

2020 ◽  
Vol 8 (20) ◽  
pp. 10310-10317
Author(s):  
Hongyan Sun ◽  
Chen Ye ◽  
Gang Zhao ◽  
Huan Zhang ◽  
Zhiduo Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Human Body ◽  
Poisson’S Ratio ◽  
Strain Sensors ◽  
Poisson's Ratio ◽  
Ratio Effect ◽  
Electronic Skin ◽  
Acoustic Signature ◽  
Signature Recognition ◽  
Ultrahigh Sensitivity

Thin film strain sensors composed of GNWs grown by MPCVD, showing ultrahigh sensitivity which can be applied for acoustic signature recognition, as well as electronic skin devices to detect both subtle and large motions of the human body.

scholarly journals Combining High Sensitivity and Dynamic Range: Wearable Thin-Film Composite Strain Sensors of Graphene, Ultrathin Palladium, and PEDOT:PSS

2019 ◽  
Vol 2 (4) ◽  
pp. 2222-2229 ◽  
Author(s):  
Julian Ramírez ◽  
Daniel Rodriquez ◽  
Armando D. Urbina ◽  
Anne M. Cardenas ◽  
Darren J. Lipomi
Keyword(s):  
Thin Film ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Strain Sensors ◽  
Film Composite ◽  
Thin Film Composite ◽  
Composite Strain

Ultrahigh Sensitivity Micro-cliff Graphene Wearable Pressure Sensor Made by Instant Flash Light Exposure

Nanoscale ◽  
2021 ◽  
Author(s):  
Yachu Zhang ◽  
Han Lin ◽  
Fei Meng ◽  
Huai Liu ◽  
David Mesa ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Pressure Sensor ◽  
Biomedical Applications ◽  
Light Exposure ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Fast Response ◽  
Highly Sensitive ◽  
Ultrahigh Sensitivity ◽  
Sensitive Pressure

Wearable and highly sensitive pressure sensors are of great importance for robotics, health monitoring and biomedical applications. Simultaneously achieving high sensitivity within a broad working range, fast response time (within...

Laser-engraved carbon nanotube paper for instilling high sensitivity, high stretchability, and high linearity in strain sensors

Nanoscale ◽  
2017 ◽  
Vol 9 (30) ◽  
pp. 10897-10905 ◽  
Author(s):  
Yangyang Xin ◽  
Jian Zhou ◽  
Xuezhu Xu ◽  
Gilles Lubineau
Keyword(s):  
Carbon Nanotube ◽  
Crack Density ◽  
High Sensitivity ◽  
Strain Sensors ◽  
High Linearity ◽  
High Crack ◽  
Ultrahigh Sensitivity

Sensors based on carbon nanotube papers with high crack density can attain ultrahigh sensitivity, high stretchability and high linearity.

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 The Effect of Encapsulation on Crack-Based Wrinkled Thin Film Soft Strain Sensors

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 364
Author(s):  
Thao Nguyen ◽  
Michael Chu ◽  
Robin Tu ◽  
Michelle Khine
Keyword(s):  
Thin Film ◽  
Large Scale ◽  
Crack Formation ◽  
Dynamic Range ◽  
Body Movement ◽  
Crack Density ◽  
High Sensitivity ◽  
Strain Sensors ◽  
Signal Recovery ◽  
Increased Sensitivity

Practical wearable applications of soft strain sensors require sensors capable of not only detecting subtle physiological signals, but also of withstanding large scale deformation from body movement. Encapsulation is one technique to protect sensors from both environmental and mechanical stressors. We introduced an encapsulation layer to crack-based wrinkled metallic thin film soft strain sensors as an avenue to improve sensor stretchability, linear response, and robustness. We demonstrate that encapsulated sensors have increased mechanical robustness and stability, displaying a significantly larger linear dynamic range (~50%) and increased stretchability (260% elongation). Furthermore, we discovered that these sensors have post-fracture signal recovery. They maintained conductivity to the 50% strain with stable signal and demonstrated increased sensitivity. We studied the crack formation behind this phenomenon and found encapsulation to lead to higher crack density as the source for greater stretchability. As crack formation plays an important role in subsequent electrical resistance, understanding the crack evolution in our sensors will help us better address the trade-off between high stretchability and high sensitivity.

Printed Graphene-Based Strain Sensors for Structural Health Monitoring

2017 ◽  
Author(s):  
Long Wang ◽  
Kenneth J. Loh ◽  
Ramin Mousacohen ◽  
Wei-Hung Chiang
Keyword(s):  
Thin Film ◽  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Structural Integrity ◽  
Strain Sensors ◽  
Metal Nanowires ◽  
Form Complex ◽  
Structural Health ◽  
Thin Film Sensors ◽  
Flexible Polymer

Strain sensors are one of the most widely used transducers for structural health monitoring, since strain can provide rich information regarding structural integrity. Recently, it has been shown that thin film sensors that incorporate nanomaterials can be engineered to possess unique properties, such as flexibility, high sensitivity, and distributed sensing capabilities, to name a few. To date, a plethora of different nanomaterials have been explored for fabricating strain sensors, such as by using conductive polymers, metal nanowires, and carbon nanotubes, among others. The aim of this work is to leverage the unique properties of graphene to fabricate next-generation thin film strain sensors. While graphene exhibits impressive mechanical and electrical properties, it remains challenging to harness these properties for sensing, primarily because of difficulties associated with high-quality synthesis and to incorporate them in a scalable fashion. In this study, few-layered graphene nano-sheets (GNS) were first synthesized using a low-cost, liquid-phase exfoliation technique. Second, GNS was dispersed in an aqueous solution with a low-concentration polymer acting as the dispersing agent. Third, the dispersion was printed onto flexible polymer substrates to form complex geometrical patterns, such as strain rosettes. Then, the electrical and electromechanical properties of the printed thin film sensors were characterized. It was found that the strain rosettes could resolve multi-axial strains applied during coupon tests. Overall, the GNS-based strain sensors showed excellent signal-to-noise ratio, stable sensing performance, high strain sensitivity, and remarkable reproducibility.

High Sensitivity pH Sensors based on Amorphous Indium-gallium-zinc Oxide Thin-film Transistors

2015 ◽  
Vol 135 (6) ◽  
pp. 192-198 ◽  
Author(s):  
Shinnosuke Iwamatsu ◽  
Yutaka Abe ◽  
Toru Yahagi ◽  
Seiya Kobayashi ◽  
Kazushige Takechi ◽  
...  
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Thin Film Transistors ◽  
High Sensitivity ◽  
Oxide Thin Film ◽  
Indium Gallium Zinc Oxide ◽  
Ph Sensors ◽  
Zinc Oxide Thin Film ◽  
Indium Gallium
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