scholarly journals The Development of Highly Flexible Stretch Sensors for a Robotic Hand

Robotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 54 ◽  
Author(s):  
Harish Devaraj ◽  
Tim Giffney ◽  
Adeline Petit ◽  
Mahtab Assadian ◽  
Kean Aw
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Black ◽  
Angular Position ◽  
Gauge Factor ◽  
Robotic Hand ◽  
Wearable Electronics ◽  
Structural Morphology ◽  
Carbon Particles ◽  
Large Stretch ◽  
Carbon Based

Demand for highly compliant mechanical sensors for use in the fields of robotics and wearable electronics has been constantly rising in recent times. Carbon based materials, and especially, carbon nanotubes, have been widely studied as a candidate piezoresistive sensing medium in these devices due to their favorable structural morphology. In this paper three different carbon based materials, namely carbon black, graphene nano-platelets, and multi-walled carbon nanotubes, were utilized as large stretch sensors capable of measuring stretches over 250%. These stretch sensors can be used in robotic hands/arms to determine the angular position of joints. Analysis was also carried out to understand the effect of the morphologies of the carbon particles on the electromechanical response of the sensors. Sensors with gauge factors ranging from one to 1.75 for strain up to 200% were obtained. Among these sensors, the stretch sensors with carbon black/silicone composite were found to have the highest gauge factor while demonstrating acceptable hysteresis in most robotic hand applications. The highly flexible stretch sensors demonstrated in this work show high levels of compliance and conformance making them ideal candidates as sensors for soft robotics.

scholarly journals Printing of Soft Stretch Sensor from Carbon Black Composites

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 732
Author(s):  
Yuteng Zhu ◽  
Mahtab Assadian ◽  
Maziar Ramezani ◽  
Kean C. Aw
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Black ◽  
Low Cost ◽  
Wearable Sensors ◽  
Nano Particles ◽  
Soft Robotics ◽  
Highly Stretchable ◽  
Resistive Material ◽  
Mechanical Sensors ◽  
Carbon Based

Demand for highly stretchable mechanical sensors for use in the fields of soft robotics and wearable sensors has been constantly rising. Carbon based materials as piezo-resistive material are low-cost and have been widely used. In this paper instead of using the controversial carbon-nanotubes, carbon black nano-particles mixed with Ecoflex® as piezo-resistive nanocomposite are used and measure strain up to 100%. Two fabrication techniques incorporating the printing (namely-“layer-upon-layer” and “embedded”) of the carbon black nanocomposite will be explored and the performances of the sensors made from these techniques will be evaluated.

scholarly journals Printability of the Screen-Printed Strain Sensor with Carbon Black/Silver Paste for Sensitive Wearable Electronics

2020 ◽  
Vol 10 (19) ◽  
pp. 6983
Author(s):  
Xue Qi ◽  
Heebo Ha ◽  
Byungil Hwang ◽  
Sooman Lim
Keyword(s):  
Carbon Black ◽  
Low Cost ◽  
Strain Sensor ◽  
High Volume ◽  
Gauge Factor ◽  
Wearable Electronics ◽  
Electronic Products ◽  
Consumer Markets ◽  
Wide Range ◽  
Low Cost Manufacturing

Printing technology enables not only high-volume, multipurpose, low-impact, low-cost manufacturing, but also the introduction of flexible electronic devices, such as displays, actuators, and sensors, to a wide range of consumer markets. Consequently, in the past few decades, printed electronic products have attracted considerable interest. Although flexible printed electronic products are attracting increasing attention from the scientific and industrial communities, a systematic study on their sensing performance based on printability has not been reported so far. In this study, carbon black/Ag nanocomposites were utilized as pastes for a flexible wearable strain sensor. The effects of the rheological property of the pastes and the pattern dimensions of the printed electrodes on the sensor’s performance were investigated. Consequently, the printed sensor demonstrated a high gauge factor of 444.5 for an applied strain of 0.6% to 1.4% with a durability of 1000 cycles and a linearity of R2 = 0.9974. The sensor was also stable under tough environmental conditions.

scholarly journals Structural Monitoring of Glass Fiber/Epoxy Laminates by Means of Carbon Nanotubes and Carbon Black Self-Monitoring Plies

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1543
Author(s):  
Lorenzo Paleari ◽  
Mario Bragaglia ◽  
Francesco Fabbrocino ◽  
Francesca Nanni
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Black ◽  
Glass Fiber ◽  
Residual Life ◽  
High Surface ◽  
Mechanical Strain ◽  
Woven Fabrics ◽  
Structural Monitoring ◽  
Gauge Factor ◽  
Self Monitoring

The health monitoring of structures is of great interest in order to check components’ structural life and monitor damages during operation. Self-monitoring materials can provide both the structural and monitoring functionality in one component and exploit their piezoresistive behavior, namely, the variation of electrical resistivity with an applied mechanical strain. In this work, self-monitoring plies were developed to be inserted into glass-fiber reinforced epoxy-based laminates in order to achieve structural monitoring. Nanocomposite epoxy-based resins were developed employing different contents of high surface area carbon black (CB, 6 wt%) and multiwall carbon nanotubes (MWCNT, 0.75 and 1 wt%), and rheologically and thermomechanically characterized. Self-monitoring plies were manufactured by impregnating glass woven fabrics with the resins, and were laminated with non-sensing plies via a vacuum-bag process to produce sensored laminates. The self-monitoring performance of the laminates was assessed during monotonic and cyclic three-point bending tests, as well as ball drop impact tests. A higher sensitivity was found for the CB-based systems (Gauge Factor 6.1), while MWCNTs (0.55 and 1.04) ensure electrical percolation at lower filler contents, as expected. The systems also showed the capability of being used to predict residual life and damage occurred under impact.

Preparation of high-crystallinity synthetic graphite from hard carbon-based carbon black

2021 ◽  
Vol 127 (2) ◽  
Author(s):  
Min Il Kim ◽  
Jong Hoon Cho ◽  
Jin Ung Hwang ◽  
Byong Chol Bai ◽  
Ji Sun Im
Keyword(s):  
Carbon Black ◽  
Hard Carbon ◽  
High Crystallinity ◽  
Synthetic Graphite ◽  
Carbon Based

Solid phase functionalization of MWNTs: an eco-friendly approach for carbon-based conductive ink.

2021 ◽  
Author(s):  
Apostolos Koutsioukis ◽  
Vassiliki Belessi ◽  
Vasilios Georgakilas
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Solid Phase ◽  
Conductive Ink ◽  
Multiwalled Carbon ◽  
Green Approach ◽  
Carbon Based

A green approach for the functionalization of multiwalled carbon nanotubes (MWNTs) with hydrophilic groups and their use for the development of an ecofriendly conductive ink is described here. A known...

scholarly journals Synthesis of silver nanoparticles embedded with single-walled carbon nanotubes for printable elastic electrodes and sensors with high stability

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jae-Won Lee ◽  
Joon Young Cho ◽  
Mi Jeong Kim ◽  
Jung Hoon Kim ◽  
Jong Hwan Park ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Silver Nanoparticles ◽  
High Performance ◽  
Composite Films ◽  
Single Walled Carbon Nanotubes ◽  
Gauge Factor ◽  
Time Interval ◽  
Single Walled Carbon ◽  
Irradiation Energy ◽  
Walled Carbon Nanotubes

AbstractSoft electronic devices that are bendable and stretchable require stretchable electric or electronic components. Nanostructured conducting materials or soft conducting polymers are one of the most promising fillers to achieve high performance and durability. Here, we report silver nanoparticles (AgNPs) embedded with single-walled carbon nanotubes (SWCNTs) synthesized in aqueous solutions at room temperature, using NaBH4 as a reducing agent in the presence of highly oxidized SWCNTs as efficient nucleation agents. Elastic composite films composed of the AgNPs-embedded SWCNTs, Ag flake, and polydimethylsiloxane are irradiated with radiation from a Xenon flash lamp within a time interval of one second for efficient sintering of conductive fillers. Under high irradiation energy, the stretchable electrodes are created with a maximum conductivity of 4,907 S cm−1 and a highly stretchable stability of over 10,000 cycles under a 20% strain. Moreover, under a low irradiation energy, strain sensors with a gauge factor of 76 under a 20% strain and 5.4 under a 5% strain are fabricated. For practical demonstration, the fabricated stretchable electrode and strain sensor are attached to a human finger for detecting the motions of the finger.

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 sp2 Carbon Stable Radicals

2021 ◽  
Vol 7 (2) ◽  
pp. 31
Author(s):  
Elena F. Sheka
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Black ◽  
Intermolecular Interaction ◽  
Open Shell ◽  
Size And Shape ◽  
Spatially Extended ◽  
Stable Radicals ◽  
The Stability ◽  
Shungite Carbon ◽  
Technological Products

sp2 Nanocarbons such as fullerenes, carbon nanotubes, and graphene molecules are not only open-shell species, but spatially extended, due to which their chemistry is quite specific. Cogently revealed dependence of the final products composition on size and shape of the carbons in use as well as on the chemical prehistory is accumulated in a particular property—the stabilization of the species’ radical efficiency, thus providing the matter of stable radicals. If the feature is highly restricted and rarely available in ordinary chemistry, in the case of sp2 nanocarbons it is just an ordinary event providing, say, tons-in-mass stable radicals when either producing such widely used technological products as carbon black or dealing with deposits of natural sp2 carbons such as anthracite, shungite carbon, and other. Suggested in the paper is the consideration of stable radicals of sp2 nanocarbons from the standpoint of spin-delocalized topochemistry. Characterized in terms of the total and atomically partitioned number of effectively unpaired electrons as well as of the distribution of the latter over carbon atoms and described by selectively determined barriers of different reactions exhibiting topological essence of intermolecular interaction, sp2 nanocarbons reveal a peculiar topokinetics that lays the foundation of the stability of their radical properties.

Polyol Synthesis of Lithium Iron Phosphate with Carbon Nanotubes: Effect of Dispersion on Crystallinity and Electrochemical Performance

2014 ◽  
Vol 1678 ◽  
Author(s):  
Wesley D. Tennyson
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Black ◽  
Lithium Iron Phosphate ◽  
Iron Phosphate ◽  
Polyol Synthesis ◽  
Battery Life ◽  
Unique Challenge ◽  
Weight Percentage ◽  
Conductive Additive ◽  
Power Capability

ABSTRACTCarbon nanotubes (CNTs) have been shown to be a viable conductive additive in Li-Ion batteries [1]. By using CNTs battery life, energy, and power capability can all be improved over carbon black, the traditional conductive additive. A significantly smaller weight percentage (5% CNTs) is needed to get the same conductivity as 20% carbon black. Many of the previous efforts found that a combination of conductive additives was most advantageous [2]. Unfortunately many of these efforts did not attend to the unique challenge that dispersing nanotubes presents and used non-optimal methods to disperse CNTs (e.g. ball milling) [3,4]. With poor dispersion a stable and resilient conductive network in the cathode is hard to form with CNTs alone. Here we investigate the formation of LiFePO₄ with CNTs using a polyol process synthesis.

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