Polypyrrole-coated Large Deformation Strain Fabric Sensor and its Properties Study

2006 ◽  
Vol 920 ◽  
Author(s):  
Xiaoyin Cheng ◽  
H. Y. J. Tsang ◽  
Y. Li ◽  
M. Y. Leung ◽  
X. M. Tao ◽  
...  
Keyword(s):  
Large Deformation ◽  
Biomedical Applications ◽  
Conductive Polymer ◽  
Strain Sensor ◽  
Chemical Vapor ◽  
High Sensitivity ◽  
Good Stability ◽  
The Past ◽  
Effects Of Temperature ◽  
Coated Fabrics

AbstractConductive-polymer coated fabrics have been investigated as intelligent materials in the past years. In this paper, a flexible fabric strain sensor coated with polypyrrole is reported, which is featured with high sensitivity, good stability and large deformation. It is fabricated by chemical vapor deposition at low temperature. The effects of temperature, humidity, acid and alkaline medium have been assessed. The conductivity-strain tests reveal the sensor exhibits a high strain sensitivity of ~160 for a deformation as large as 50%, while its good stability is indicated by a small loss of conductivity after the thermal and humidity aging tests, and supported by the slight change in conductivity and sensitivity over a storage of eighteen months. The acid and alkaline solution mainly decreased their initial conductivity but have the slight effect to their sensitivity. The flexible fabric strain sensor is expected to be a promising “soft” smart material in the smart garment, wearable hardware and biomedical applications.

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.

scholarly journals Highly Sensitive Ultrathin Flexible Thermoplastic Polyurethane/Carbon Black Fibrous Film Strain Sensor with Adjustable Scaffold Networks

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Xin Wang ◽  
Xianhu Liu ◽  
Dirk W. Schubert
Keyword(s):  
Carbon Black ◽  
High Performance ◽  
Electrical Response ◽  
Thermoplastic Polyurethane ◽  
Conductive Polymer ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Human Motion ◽  
Electrospinning Process ◽  
Gauge Factor

AbstractIn recently years, high-performance wearable strain sensors have attracted great attention in academic and industrial. Herein, a conductive polymer composite of electrospun thermoplastic polyurethane (TPU) fibrous film matrix-embedded carbon black (CB) particles with adjustable scaffold network was fabricated for high-sensitive strain sensor. This work indicated the influence of stereoscopic scaffold network structure built under various rotating speeds of collection device in electrospinning process on the electrical response of TPU/CB strain sensor. This structure makes the sensor exhibit combined characters of high sensitivity under stretching strain (gauge factor of 8962.7 at 155% strain), fast response time (60 ms), outstanding stability and durability (> 10,000 cycles) and a widely workable stretching range (0–160%). This high-performance, wearable, flexible strain sensor has a broad vision of application such as intelligent terminals, electrical skins, voice measurement and human motion monitoring. Moreover, a theoretical approach was used to analyze mechanical property and a model based on tunneling theory was modified to describe the relative change of resistance upon the applied strain. Meanwhile, two equations based from this model were first proposed and offered an effective but simple approach to analyze the change of number of conductive paths and distance of adjacent conductive particles.

How SIMS microscopy can be used in medicine

1992 ◽  
Vol 50 (2) ◽  
pp. 1602-1603
Author(s):  
Philippe Fragu
Keyword(s):  
Mass Spectrometry ◽  
Biomedical Applications ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Elements ◽  
Biological Applications ◽  
The Past ◽  
Potential Source ◽  
Secondary Ion ◽  
Chemical Integrity ◽  
Scientific Endeavour

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.

scholarly journals Flexible Metal/Polymer Composite Films Embedded with Silver Nanowires as a Stretchable and Conductive Strain Sensor for Human Motion Monitoring

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 372 ◽  
Author(s):  
Jinjin Luan ◽  
Qing Wang ◽  
Xu Zheng ◽  
Yao Li ◽  
Ning Wang
Keyword(s):  
Polymer Composite ◽  
Silver Nanowires ◽  
Composite Films ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Human Motion ◽  
Applied Strain ◽  
Potential Candidate ◽  
Flexible Metal ◽  
Metal Polymer

To avoid conductive failure due to the cracks of the metal thin film under external loads for the wearable strain sensor, a stretchable metal/polymer composite film embedded with silver nanowires (AgNWs) was examined as a potential candidate. The combination of Ag film and AgNWs enabled the fabrication of a conductive film that was applied as a high sensitivity strain sensor, with gauge factors of 7.1 under the applied strain of 0–10% and 21.1 under the applied strain of 10–30%. Furthermore, the strain sensor was demonstrated to be highly reversible and remained stable after 1000 bending cycles. These results indicated that the AgNWs could act as elastic conductive bridges across cracks in the metal film to maintain high conductivity under tensile and bending loads. As such, the strain sensor engineered herein was successfully applied in the real-time detection and monitoring of large motions of joints and subtle motions of the mouth.

Chitosan/Polyethylene Oxide (PEO) Filled Carbonized Wood Fiber Conductive Composite Film

2020 ◽  
Vol 1010 ◽  
pp. 638-644
Author(s):  
Mohd Pisal Mohd Hanif ◽  
Abd Jalil Jalilah ◽  
Mohd Fadzil Hanim Anisah ◽  
Arumugam Tilagavathy
Keyword(s):  
Electrical Conductivity ◽  
Tensile Strength ◽  
Polyethylene Oxide ◽  
Biomedical Applications ◽  
Wood Fiber ◽  
Conductive Polymer ◽  
Renewable Resource ◽  
Blend Films ◽  
Conductive Composite Film ◽  
Carbonized Wood

Biopolymer-based conductive polymer composites (CPCs) would open up various possibilities in biomedical applications owing to ease of processing, renewable resource and environmentally friendly. However, low mechanical properties are a major issue for their applications. In this study, the investigated the conductivity of chitosan/ PEO blend films filled with carbonized wood fiber (CWF) prepared by solution casting. The effect of CWF was also investigated on tensile properties and their morphological surfaces. The tensile results from different ratios of chitosan/PEO blend films without CWF show that the tensile strength and modulus increased with the increase of chitosan content and chitosan/PEO blend film with 70/30 ratio exhibited the best combination of tensile strength and flexibility. However, a reduction of tensile strength was observed when CWF amount was increased while the modulus of the tensile shows an increment. The film also exhibited higher electrical conductivity as compared to low chitosan ratio. The addition of CWF greatly enhanced the conductivity three-fold from 10-10 to 10-6 S/cm. The electrical conductivity continued to increase with the increase of CWF up to 30wt%. The surface morphology by Scanning Electron Microscopy (SEM) exhibits the absence of phase separation for the blends indicating good miscibility between the PEO and chitosan. Incorporation of CWF into the blend films at 5wt% showed agglomeration. However, the increase of CWF created larger agglomerations that formed conductive pathways resulting in improved conductivity. FTIR analysis suggested that intermolecular interactions occurred between chitosan and PEO while CWF interacts more with the protons of PEO.

Superhydrophobic gradient wrinkle strain sensor with ultra-high sensitivity and broad strain range for motion monitoring

2021 ◽  
Vol 9 (15) ◽  
pp. 9634-9643
Author(s):  
Zhenming Chu ◽  
Weicheng Jiao ◽  
Yifan Huang ◽  
Yongting Zheng ◽  
Rongguo Wang ◽  
...  
Keyword(s):  
Human Body ◽  
Full Range ◽  
Strain Sensor ◽  
Strain Range ◽  
High Sensitivity

A graphene-based gradient wrinkle strain sensor with a broad range and ultra-high sensitivity was fabricated by a simple pre-stretching method. It can be applied to the detection of full-range human body motions.

scholarly journals Design of a Sensitive Balloon Sensor for Safe Human–Robot Interaction

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2163
Author(s):  
Dongjin Kim ◽  
Seungyong Han ◽  
Taewi Kim ◽  
Changhwan Kim ◽  
Doohoe Lee ◽  
...  
Keyword(s):  
High Performance ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Human Robot Interaction ◽  
Large Area ◽  
Tactile Sensors ◽  
Robot Interaction ◽  
Mechanical Crack ◽  
Flexible Strain Sensor ◽  
Contact Sensing

As the safety of a human body is the main priority while interacting with robots, the field of tactile sensors has expanded for acquiring tactile information and ensuring safe human–robot interaction (HRI). Existing lightweight and thin tactile sensors exhibit high performance in detecting their surroundings. However, unexpected collisions caused by malfunctions or sudden external collisions can still cause injuries to rigid robots with thin tactile sensors. In this study, we present a sensitive balloon sensor for contact sensing and alleviating physical collisions over a large area of rigid robots. The balloon sensor is a pressure sensor composed of an inflatable body of low-density polyethylene (LDPE), and a highly sensitive and flexible strain sensor laminated onto it. The mechanical crack-based strain sensor with high sensitivity enables the detection of extremely small changes in the strain of the balloon. Adjusting the geometric parameters of the balloon allows for a large and easily customizable sensing area. The weight of the balloon sensor was approximately 2 g. The sensor is employed with a servo motor and detects a finger or a sheet of rolled paper gently touching it, without being damaged.

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