Temperature-dependent electrical properties of graphene nanoplatelets film dropped on flexible substrates

Tian, Mengkui; Huang, Ying; Wang, Weihua; Li, Ruiqi; Liu, Ping; Liu, Caixia; Zhang, Yugang

doi:10.1557/jmr.2014.109

Cited by 50 publications

(31 citation statements)

References 35 publications

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“…While this paper is focused on ECG sensing, these graphene electrodes can also be applied to other electrophysiological sensing methods, such as EMG and EEG. Additionally, graphene has pressure sensitivity properties [31,32], and its impedance changes with temperature [33]; using a combination of these properties, the development of wearable integrated multidimensional physiological information detection sensors may be feasible.…”

Section: Discussionmentioning

confidence: 99%

Flexible Graphene Electrodes for Prolonged Dynamic ECG Monitoring

Lou

et al. 2016

Sensors

116

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This paper describes the development of a graphene-based dry flexible electrocardiography (ECG) electrode and a portable wireless ECG measurement system. First, graphene films on polyethylene terephthalate (PET) substrates and graphene paper were used to construct the ECG electrode. Then, a graphene textile was synthesized for the fabrication of a wearable ECG monitoring system. The structure and the electrical properties of the graphene electrodes were evaluated using Raman spectroscopy, scanning electron microscopy (SEM), and alternating current impedance spectroscopy. ECG signals were then collected from healthy subjects using the developed graphene electrode and portable measurement system. The results show that the graphene electrode was able to acquire the typical characteristics and features of human ECG signals with a high signal-to-noise (SNR) ratio in different states of motion. A week-long continuous wearability test showed no degradation in the ECG signal quality over time. The graphene-based flexible electrode demonstrates comfortability, good biocompatibility, and high electrophysiological detection sensitivity. The graphene electrode also combines the potential for use in long-term wearable dynamic cardiac activity monitoring systems with convenience and comfort for use in home health care of elderly and high-risk adults.

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Section: Discussionmentioning

confidence: 99%

Flexible Graphene Electrodes for Prolonged Dynamic ECG Monitoring

Lou

et al. 2016

Sensors

116

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“…[1][2][3][4][5][6] A lot of research focuses on the electronic skin systems based on resistive, capacitive, and piezoelectric. [7][8][9] Recently, flexible composites with piezoresistive properties have been proved to be a good choice since these materials are able to reproduce the tactile sense and fit the shape of the robot structure, obtaining the high conformability required to mimic the human skin and being able to obtain metrical information with high precision and high resolution.…”

Section: Introductionmentioning

confidence: 99%

A multilayered flexible piezoresistive sensor for wide-ranged pressure measurement based on CNTs/CB/SR composite

et al. 2015

Self Cite

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To optimize the structure of the flexible piezoresistive sensor based on conductive polymer composite and widen the workable pressure range, a piezoresistive sensor with a multilayered structure based on carbon nanotubes/carbon black/silicone rubber conductive composite was designed and investigated. Different from the traditional monolayer structure, this novel multilayered sensor consisted of three microstructured piezoresistive composite films. The experimental data showed that the electrical resistance of the sensor varied regularly with a wide range of applied pressure (0-1.8 MPa at least). The high sensitivity, high flexibility, facile fabrication, and low cost were also the advantages of this pressure sensor. In addition, the piezoresistive mechanism was studied and shown to be the synergistic effects of the contact resistance mechanism and bulk resistance mechanism. Factors influencing the piezoresistive properties were also investigated. Moreover, the consecutive loading tests verified the feasibility and stability to use this sensor element for pressure measurement.

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“…[ 16,17 ] Figure 2 C illustrates the three mixing phases described above. During the infi ltration, the polymeric solution goes into the void of the CB agglomerates and can be considered as being part of the fi ller, as a consequence the volume of the free polymer becomes smaller.…”

Section: Wileyonlinelibrarycommentioning

confidence: 99%

“…The incorporation of the CB into PAI-nanocomposite fi lms, however, has been confi rmed by the presence of peaks around 1750 cm −1 , which can be assigned to carboxyl and carbonyl groups. [ 17,18 ] Figure 3 B shows the DSC curves, comparing the PAI fi lm without nanofi llers and the fi lm with the highest CB concentration (30 wt%). In the considered temperature range (30-300 °C) no glass transition or melting point is observed.…”

Section: Wileyonlinelibrarycommentioning

confidence: 99%

“…[ 16 ] Thin conductive heating layers, for de-icing applications, have been produced by dropping graphene nanoplatelets onto a fl exible substrate. [ 17 ] For some applications, however, very low fi ller concentrations are a serious drawback in obtaining high thermal effi ciency and allowing good heat dissipation. The power generated by Joule heating along few fi ller pathways and the low thermal conductivity resulting from the high content of insulating polymer lead to a strong thermal gradient within the material.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Flexible Poly(Amide‐Imide)‐Carbon Black Based Microheater with High‐Temperature Capability and an Extremely Low Temperature Coefficient

Liparoti

Landi

Sorrentino

et al. 2016

Adv Elect Materials

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heating element comprises a conductive polymer material. Polymer loaded with conducting fi llers such as carbon-based materials and metal fi bers have been extensively investigated owing to their lightweight and good processability. [1][2][3][4] They are ideal for many smart applications, such as patternable microheaters, temperature sensors, thermoelectric devices, water heaters, and fl exible deicing units. [5][6][7] However, up to now low values of dielectric strength, dimensional stability, thermal insulation, electrical power density, and maximum operating temperature have limited their applications in fl exible heater manufacturing. [ 8,9 ] So far, metal-based microheaters on fl exible foils are the dominant approach in the fi eld. The substitution of conventional microheaters with polymer-based microheaters can expand their applications to extreme environments or for cases, where space and weight allowances are limited. Several approaches related to their formulation and processing have been proposed to overcome the limitations of purely polymer-based solutions. Nanosized particles have received great attention due to their electrical cycle stability and their potential in processing thin fi lms with uniform morphology. In this case, a number of new problems, such as signifi cant particle agglomeration, high interface fraction, and porosity in polymer matrices need to be resolved during nanocomposite production. Probably, the most important issue is the fi ller distribution within the matrix, which depends strongly on the right combination of processing conditions (pressure, temperature, humidity, mixing, etc.), formulation (fi ller content, properties of the matrix), and particle-matrix interactions. [ 10 ] Controlling the impact of all these parameters allows to fi nd the right balance between dispersion and aggregation phenomena in order to prevent either the formation of microagglomerates or of conductive pathway breakage. Generally, it is preferable to decrease the fi ller content value at which the composite becomes conductive (percolation threshold). This is generally achieved by partial segregation of the fi ller or by using conductive nanometric fi llers with high aspect ratio. Among these, nanocarbon materials such as carbon nanotubes (CNTs), graphene, and carbon nanofi bers are used to obtain highly conductive polymer composites with a very low Flexible poly(amide-imide)-carbon black (PAI-CB) composite fi lms, to be applied as high performance microheater foil, have been prepared with a solution/casting technique. The CB dispersion has been carefully controlled in order to improve the thermal and electrical properties of the resulting composites. Morphology and structure of the PAI-CB composite fi lms have been characterized by optical microscopy, atomic force microscopy and FTIR spectroscopy. The effect of the CB dispersion and its interaction with the polymer chains on the thermal and mechanical properties of the composite fi lms have been investigated by using differential scanning calorimetr...

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Temperature-dependent electrical properties of graphene nanoplatelets film dropped on flexible substrates

Cited by 50 publications

References 35 publications

Flexible Graphene Electrodes for Prolonged Dynamic ECG Monitoring

Flexible Graphene Electrodes for Prolonged Dynamic ECG Monitoring

A multilayered flexible piezoresistive sensor for wide-ranged pressure measurement based on CNTs/CB/SR composite

Flexible Poly(Amide‐Imide)‐Carbon Black Based Microheater with High‐Temperature Capability and an Extremely Low Temperature Coefficient

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