Shape-driven arrest of coffee stain effect drives the fabrication of carbon-nanotube-graphene-oxide inks for printing embedded structures and temperature sensors

Abstract

Carbon nanotube (CNT) based binder-free, syringe-printable inks, with graphene oxide being used as dispersants, have been designed and developed based on the unique ellipsoidal-particle-shape-mediated arrest of the coffee-stain effect.

Ultrathin and Ultrasensitive Printed Carbon Nanotube-Based Temperature Sensors Capable of Repeated Uses on Surfaces of Widely Varying Curvatures and Wettabilities

“…For example, for some of the specimens, the resistance decreases at low temperatures (i.e., when the temperature changed from 10 to 25 ° C) are five times larger in comparison to the resistance change at higher temperatures (i.e., when the temperature further changed from 25 to 50 ° C). In our previous study, we noticed an averaged linear TCR [ ] of α ≈ – 0.7 × 10 –3 / ° C to α ≈ – 2 × 10 –3 / ° C for CNT-GO trace (with a GO:CNT weight ratio of 1:1)-printed straight-line traces and sensor patterns in the temperature range of 26 to 80 ° C. We also measured the average resistance drop, which was approximately −3.5 Ω/ ° C for the sensor patterns printed with this ink. All those measurements were conducted on flat substrates .…”

“…The GO agglomeration regions could be observed in both situations (before and after treatments such as bending, folding, and cycles of temperature-resistance testing) (see Figure a-iii,b-iii), and no obvious damage (such as cracks) or changes in microarchitecture were observed on the traces printed on PET. Of course, unlike our previous paper, the CNT networks are not distinctly visible, stemming from the fact that we employed ESEM here and avoided the use of conductive coatings during the specimen preparation, making the specimens less conductive.…”

“…The ink was subjected to 30 h of sonication during the preparation process, and before each printing, it was sonicated for an additional half an hour to ensure that it remained well dispersed. The fabricated ink showed a shear-thinning behavior, characterized by its viscosity decreasing from approximately 10 2 Pa·s to 10 –3 Pa·s as the shear rate increased from 10 –3 to 10 2 s –1 . Such shear-thinning behavior is necessary to make the ink syringe printable. , …”

Boron Nitride Nanotube–Salt–Water Hybrid: Toward Zero-Dimensional Liquid Water and Highly Trapped Immobile Single Anions Inside One-Dimensional Nanostructures

“…Nanotubes (e.g., carbon nanotubes or CNTs and boron nitride nanotubes or BNNTs), characterized as hollow tubes with internal diameters ranging from a few to tens of nanometers have emerged as the most remarkable one-dimensional (1D) nanostructures that have found wide-scale application in fabrication of sensors, transistors, conductors, batteries, energy-storage materials, light-emitting diodes, lithium-ion batteries, supercapacitors, light-weight composites, and flexible electronics as well as in applications such as waste-water treatment, water purification, chromatography, voltammetry, solid-phase extraction of drugs and biomolecules, drug targeting, controlled drug release, disease diagnosis and treatment, enabling antibacterial and antifungal properties, and many more. − While many of these applications use these nanotubes as filler materials for improving the properties of certain macroscopic materials (e.g., adding CNTs for improving the mechanical, thermal, and electric properties of CNT-polymer-based nanocomposites − or using CNTs to prepare mixtures/pastes that can be used for printing temperature sensors , and fabricating antibacterial coatings , ), more exciting classes of studies and future applications (e.g., use as high-performance membranes, or use in futuristic water treatment technologies, or promoting specific chemical reactions) involve probing the properties and transport of water, ions, and other species (e.g., alcohol, dyes, etc.) remaining encapsulated within or transporting through a single CNT or BNNT. − For example, water encapsulated within CNTs or BNNTs demonstrates a 1D structure with most fascinating properties. − Similarly, gas-filled CNTs have been touted to be used as nanoresonators with unprecedented properties. − Also, there has been massive interest in probing the behavior of nanotube-encapsulated salt systems. − One such example, where other species have been closely integrated with nanotubes, is nanotube–molecule-based hybrid systems.…”

Airflow-assisted dielectrophoresis to reduce the resistance mismatch in carbon nanotube-based temperature sensors

“…In the rst case, limited studies addressed sensors that use only CNTs (either single-walled carbon nanotubes (SWCNTs) or multiwalled carbon nanotubes (MWCNTs)) to detect temperature variation. 20,21 In the second case, the sensing material was manufactured by mixing CNTs with other materials such as epoxy resin, 22 poly(vinylidene uoride) (PVDF), 23 graphene oxide, 24 silicon, 25 and PEDOT:PSS. 26 In both cases, CNTs are preferred to be aligned in order to achieve their best performance.…”