scholarly journals Fabrication of Piezo-Resistance Composites Containing Thermoplastic Polyurethane/Hybrid Filler Using 3D Printing

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6813
Author(s):  
Kyoungho Song ◽  
Hansol Son ◽  
Suwon Park ◽  
Jonghan Lee ◽  
Jungsik Jang ◽  
...  
Keyword(s):  
Thermoplastic Polyurethane ◽  
Pressure Sensors ◽  
Strain Range ◽  
Electrical Network ◽  
Gauge Factor ◽  
Hybrid Filler ◽  
Hybrid Fillers ◽  
Potential Applications ◽  
Multi Walled Carbon Nanotubes ◽  
Piezoresistive Pressure Sensors

In this study, 3D-printable flexible piezoresistive composites containing various amounts of cilia-like hybrid fillers were developed. In the hybrid fillers, micro-scale Cu particles with a 0D structure may allow them to easily disperse into the flexible TPU matrix. Furthermore, nanoscale multi-walled carbon nanotubes (MWCNTs) with a high aspect ratio, present on the surface of the Cu particles, form an electrical network when the polymer matrix is strained, thus providing good piezoresistive performance as well as good flowability of the composite materials. With an optimal hybrid filler content (17.5 vol.%), the 3D-printed piezoresistive composite exhibits a gauge factor of 6.04, strain range of over 20%, and durability of over 100 cycles. These results highlight the potential applications of piezoresistive pressure sensors for health monitoring, touch sensors, and electronic skin.

scholarly journals Synergistic Effect of Graphene/Silver Nanowire Hybrid Fillers on Highly Stretchable Strain Sensors Based on Spandex Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2063
Author(s):  
Tan Thong Vo ◽  
Hyeon-Jong Lee ◽  
Sang-Yun Kim ◽  
Ji Won Suk
Keyword(s):  
Synergistic Effect ◽  
High Performance ◽  
Silver Nanowires ◽  
Large Strain ◽  
Strain Range ◽  
Strain Sensors ◽  
Silver Nanowire ◽  
Gauge Factor ◽  
Hybrid Fillers ◽  
Conductive Nanomaterials

Embedding conductive nanomaterials into elastomeric polymer matrices is one of the most promising approaches for fabricating stretchable strain sensors capable of monitoring large mechanical movements or deformation through the detection of resistance changes. Here, hybrid fillers comprising graphene and silver nanowires (AgNWs) are incorporated into extremely stretchable spandex to fabricate strain sensors. Composites containing only graphene and those containing the graphene/AgNW hybrid fillers are systematically investigated by evaluating their electrical and mechanical properties. The synergistic effect between graphene and AgNWs enable the strain sensors based on the composites to experience a large strain range of up to 120%, and low hysteresis with a high gauge factor of 150.3 at a strain of 120%. These reliable strain sensors are utilized for monitoring human motions such as heartbeats and body movements. The findings of this study indicate the significant applicability of graphene/AgNW/spandex composites in future applications that demand high-performance stretchable strain sensors.

scholarly journals Wrinkle Structured Network of Silver-Coated Carbon Nanotubes for Wearable Sensors

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Zhongyun Yuan ◽  
Zhen Pei ◽  
Muhammad Shahbaz ◽  
Qiang Zhang ◽  
Kai Zhuo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dynamic Range ◽  
Wearable Sensors ◽  
Hand Movement ◽  
Strain Range ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Gauge Factor ◽  
Resistance Change ◽  
Multi Walled Carbon Nanotubes

AbstractSoft-strain-based sensors are being increasingly used across various fields, including wearable sensing, behavior monitoring, and electrophysiological diagnostics. However, throughout all applications, the function of these sensors is limited because of high sensitivity, high-dynamic range, and low-power consumption. In this paper, we focus on improving the sensitivity and strain range of the soft-strain-based sensor through structure, surface, and sensitive unit treatment. Nanosilver (Ag)-coated hydroxyl-functionalized multi-walled carbon nanotubes (OH-f MWCNTs) were explored for highly acute sensing. With stretching and depositing methods, Ag@OH-f MWCNTs and polydimethylsiloxane (PDMS) are fabricated into a wrinkled and sandwich structure for a soft-strain-based sensor. The electronic properties were characterized in that the gauge factor (GF) = ΔR/R0 was 412.32, and the strain range was 42.2%. Moreover, our soft-strain-based sensor exhibits features including flexibility, ultra-lightweight and a highly comfortable experience in terms of wearability. Finally, some physiological and behavioral features can be sampled by testing the exceptional resistance change, including the detection of breath, as well as facial and hand movement recognition. The experiment exhibits its superiority in terms of being highly sensitive and having an extensive range of sensing.

scholarly journals On the Synergistic Effect of Multi-Walled Carbon Nanotubes and Graphene Nanoplatelets to Enhance the Functional Properties of SLS 3D-Printed Elastomeric Structures

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1841 ◽  
Author(s):  
Gennaro Rollo ◽  
Alfredo Ronca ◽  
Pierfrancesco Cerruti ◽  
Xin Peng Gan ◽  
Guoxia Fei ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Functional Properties ◽  
Thermoplastic Polyurethane ◽  
Selective Laser Sintering ◽  
Gauge Factor ◽  
Porous Structures ◽  
Elastomeric Matrix ◽  
Unit Cells ◽  
Multi Walled Carbon Nanotubes ◽  
Electro Magnetic

Elastomer-based porous structures realized by selective laser sintering (SLS) are emerging as a new class of attractive multifunctional materials. Herein, a thermoplastic polyurethane (TPU) powder for SLS was modified by 1 wt.% multi-walled carbon nanotube (MWCNTs) or a mixture of MWCNTs and graphene (GE) nanoparticles (70/30 wt/wt) in order to investigate on both the synergistic effect provided by the two conductive nanostructured carbonaceous fillers and the correlation between formulation, morphology, and final properties of SLS printed porous structures. In detail, porous structures with a porosity ranging from 20% to 60% were designed using Diamond (D) and Gyroid (G) unit cells. Results showed that the carbonaceous fillers improve the thermal stability of the elastomeric matrix. Furthermore, the TPU/1 wt.% MWCNTs-GE-based porous structures exhibit excellent electrical conductivity and mechanical strength. In particular, all porous structures exhibit a robust negative piezoresistive behavior, as demonstrated from the gauge factor (GF) values that reach values of about −13 at 8% strain. Furthermore, the G20 porous structures (20% of porosity) exhibit microwave absorption coefficients ranging from 0.70 to 0.91 in the 12–18 GHz region and close to 1 at THz frequencies (300 GHz–1 THz). Results show that the simultaneous presence of MWCNTs and GE brings a significant enhancement of specific functional properties of the porous structures, which are proposed as potential actuators with relevant electro-magnetic interference (EMI) shielding properties.

3D-Printed Stretchable Strain Sensor With Application to Wind Sensing

2018 ◽  
Author(s):  
Mohammed Al-Rubaiai ◽  
Ryohei Tsuruta ◽  
Umesh Gandhi ◽  
Chuan Wang ◽  
Xiaobo Tan
Keyword(s):  
Wind Speed ◽  
Large Strain ◽  
Thermoplastic Polyurethane ◽  
Strain Sensor ◽  
Strain Range ◽  
Strain Sensors ◽  
Plastic Substrate ◽  
Gauge Factor ◽  
Effective Manner ◽  
3D Printed

Stretchable strain sensors with large strain range, high sensitivity, and excellent reliability are of great interest for applications in soft robotics, wearable devices, and structure-monitoring systems. Unlike conventional template lithography-based approaches, 3D-printing can be used to fabricate complex devices in a simple and cost-effective manner. In this paper, we report 3D-printed stretchable strain sensors that embeds a flexible conductive composite material in a hyper-plastic substrate. Three commercially available conductive filaments are explored, among which the conductive thermoplastic polyurethane (ETPU) shows the highest sensitivity (gauge factor of 5), with a working strain range of 0%–20%. The ETPU strain sensor exhibits an interesting behavior where the conductivity increases with the strain. In addition, an experiment for measuring the wind speed is conducted inside a wind tunnel, where the ETPU sensor shows sensitivity to the wind speed beyond 5.6 m/s.

scholarly journals Thermal Properties of TiO2NP/CNT/LDPE Hybrid Nanocomposite Films

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1270 ◽  
Author(s):  
Moustafa Zagho ◽  
Mariam AlMaadeed ◽  
Khaliq Majeed
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Composite Films ◽  
Nanocomposite Films ◽  
Filler Concentration ◽  
Gravimetric Analysis ◽  
Melt Mixing ◽  
Hybrid Filler ◽  
Hybrid Fillers ◽  
Multi Walled Carbon Nanotubes

This work aims to investigate the effect of hybrid filler concentration on the thermal stability of low-density polyethylene (LDPE) matrices. LDPE-based composite films were synthesized by melt mixing, followed by compression molding, to study the influence of titanium oxide nanoparticles (TONPs) and/or multi-walled carbon nanotubes (CNTs) on the thermal properties of LDPE matrices. Fourier transform infrared (FTIR) spectroscopy confirmed the slight increase in the band intensities after TONP addition and a remarkable surge after the incorporation of CNTs. The value of crystallization temperature (Tc) was not modified after incorporating TONPs, while an enhancement was observed after adding the hybrid fillers. The melting temperature (Tm) was not changed after introducing the CNTs and CNT/TONP hybrid fillers. The percentage crystallinity (Xc %) was increased by 4% and 6%, after incorporating 1 wt % and 3 wt % CNTs, respectively. The TONP incorporation did not modify the Xc %. Moreover, thermal gravimetric analysis (TGA) thermograms confirmed the increased thermal stability after introducing CNTs and hybrid fillers compared to TONP incorporation.

scholarly journals Piezoresistive Behaviour of Additively Manufactured Multi-Walled Carbon Nanotube/Thermoplastic Polyurethane Nanocomposites

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2613 ◽  
Author(s):  
Myoungsuk Kim ◽  
Jaebong Jung ◽  
Sungmook Jung ◽  
Young Hoon Moon ◽  
Dae-Hyeong Kim ◽  
...  
Keyword(s):  
Large Scale ◽  
Thermoplastic Polyurethane ◽  
Pressure Sensors ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Multi Walled Carbon Nanotubes ◽  
Flexible Pressure Sensors ◽  
Walled Carbon Nanotubes

To develop highly sensitive flexible pressure sensors, the mechanical and piezoresistive properties of conductive thermoplastic materials produced via additive manufacturing technology were investigated. Multi-walled carbon nanotubes (MWCNTs) dispersed in thermoplastic polyurethane (TPU), which is flexible and pliable, were used to form filaments. Specimens of the MWCNT/TPU composite with various MWCNT concentrations were printed using fused deposition modelling. Uniaxial tensile tests were conducted, while the mechanical and piezoresistive properties of the MWCNT/TPU composites were measured. To predict the piezoresistive behaviour of the composites, a microscale 3D resistance network model was developed. In addition, a continuum piezoresistive model was proposed for large-scale simulations.

Ultrasensitive, flexible, and low-cost nanoporous piezoresistive composites for tactile pressure sensing

Nanoscale ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 2779-2786 ◽  
Author(s):  
Jing Li ◽  
Santiago Orrego ◽  
Junjie Pan ◽  
Peisheng He ◽  
Sung Hoon Kang
Keyword(s):  
Carbon Nanotube ◽  
Polymer Composites ◽  
Low Cost ◽  
Pressure Sensors ◽  
Nanoporous Carbon ◽  
Pressure Sensing ◽  
Etching Method ◽  
Piezoresistive Pressure Sensors

We report a facile sacrificial casting–etching method to synthesize nanoporous carbon nanotube/polymer composites for ultra-sensitive and low-cost piezoresistive pressure sensors.

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