Flexible Conductive Substrates Research Articles

Ultrafast In-Situ synthesis of flexible MoO3 anode in five seconds for High-Performance aqueous zinc ion hybrid capacitor

The efficient synthesis of high-performance α-MoO3 on flexible conductive substrates is crucial for enhancing its value in the field of energy storage. However, traditional synthesis methods currently employed often suffer from slow heating rates, intricate reaction processes involving multiple steps, sluggish reaction kinetics, high energy consumption, and prolonged preparation times, thereby hindering efficient production. Presented herein is a facile, ultrafast, and versatile approach utilizing microwave carbon thermal shock, a one-step reaction synthesis of α-MoO3 on carbon substrates within 5 s. During microwave carbon thermal shock, the precursor salt experiences an extremely rapid heating rate, swiftly decomposing to form small-sized α-MoO3 crystals. Simultaneously, this process promotes the oxidation of adjacent carbon sites, thereby imparting multi-scale defects and oxygen-containing functional groups to the resulting carbon cloth (CC). The exceptionally low reaction energy barriers and superior Gibbs free energy (ΔG) further substantiate the advantages of the microwave carbon thermal shock strategy over traditional synthesis methods in terms of both kinetics and thermodynamics. The air-assisted transient microwave carbonthermal shock (AMCTS) process circumvents high energy requirements, multistep reactions, and extended preparation times, endowing AMCTS-CC@MoO3 with remarkable flexibility and processability. In demonstrating its practical utility within zinc-ion hybrid micro capacitors, it exhibits outstanding specific capacitance (up to 2300mF cm−2) and mechanical stability. This air-assisted transient microwave thermal shock process provides an efficient route for ultrafast and low-cost synthesis of flexible zinc-ion anode materials.

Towards the fabrication of fully printed flexible P(VDF-TrFE)-based piezoelectric sensors

The emergent Internet of Things (IoT) market has increased the need of sensors, actuators and nanogenerators, demanding cost-effective and large-scale manufacturing methods to fabricate these devices. Printed electronics (PE), which consists of the application printing and coating technologies in the deposition of functional materials, is one of the ways to process low-cost lightweight, semi-transparent, and flexible devices, usually employing polymers as functional materials. In this work we present the fabrication of poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) copolymer-based printed piezoelectric devices applying different semi-transparent flexible conductive substrates as bottom electrodes. The screen-printing process was chosen as a large-scale cost-effective fabrication method at low-temperature processing. Printing and the laser scribing parameters were established, and the effectively use of silver and PEDOT:PSS as top electrodes was demonstrated. The final devices were electrically poled and characterized by Electrochemical Impedance Spectroscopy (EIS) and correlations among the device’ performance regarding the different bottom and top electrodes were set up, leading to processing recommendations. Employing a cycle olefin polymer coated with silver nanowires (AgNW) as substrate, P(VDF-TrFE) as active material and silver as top electrode, a 223 µF/m2 capacitance was obtained when compressing at 2.37 KPa, demonstrating the devices charge storage capacity by the application of a mechanical stress. All the employed processing conditions can be easily integrated in a R2R pilot line, allowing high throughput, low-cost and large-area manufacturing. Additionally, the use of the polymer substrates enables the fabrication of flexible and lightweight devices.

High-Performance Flexible Ionically Conductive Superhydrophobic Papers via Deep Eutectic Polymer-Enhanced Interfacial Interactions.

Endowing paper with highly flexible, conductive, and superhydrophobic properties will effectively expand its applications in fields such as green packaging, smart sensing, and paper-based electronics. Herein, a multifunctional superhydrophobic paper is reported in which a highly flexible transparent conductive substrate is prepared by introducing a hydrophobic deep eutectic polymer into the ethylcellulose network via a matrix swelling-polymerization strategy, and then the substrate is modified using fluorinated silica to impart superhydrophobicity. By introducing soft deep eutectic polymers, (1) the superhydrophobic paper can efficiently dissipate energy during deformation, (2) intrinsically ion-conducting deep eutectic polymers can endow the material with good electrical sensing properties, and (3) meanwhile, enhanced interfacial interactions can anchor inorganic particles, thereby improving the coating stability. The prepared superhydrophobic paper has an ultrahigh water contact angle (contact angle ≈ 162.2°) and exhibits a stable electrical response signal to external deformation/pressure, and the electrical properties are almost unaffected by external water molecules. In addition, the superhydrophobic paper was able to withstand 5000 bending-recovery cycles at a large angle of 150°, exhibiting stable electrical performance. The design concepts demonstrated here will provide insights into the development of superhydrophobic paper-based flexible electronic devices.

Tough and Self-Healing Waterborne Polyurethane Elastomers via Dynamic Hydrogen Bonds Design for Flexible Conductive Substrate Applications.

Balancing the mechanical strength and self-healing performance of polyurethane (PU) remains a significant challenge in achieving excellent self-repairing PU materials. In this study, a self-healing waterborne PU elastomer was designed from a bionic concept by incorporating 2'-deoxythymidine (2'-dT) and isophorone diamine (IPDA) into the polymer chain. The loose stacking of IPDA's irregular cycloaliphatic structure resulted in the irregular arrangement of urethane bonds in the hard domain. The formation of sextuple hydrogen bonds between 2'-dT and urethane bonds, as well as quadruple hydrogen bonds between urethane bonds themselves, enhanced the mechanical properties of the material. The multiple hydrogen bonds can dissociate, recombine, and dissipate energy, thereby improving the material's repair capability. The hierarchical self-assembly of hydrogen bonds enabled the PU to achieve a tensile strength of 15.3 MPa and toughness of 100.75 MJ/m3. The prepared PU film is highly transparent and has a transmittance of more than 90%. Additionally, it can undergo rapid repair under high temperatures or under trace solvent conditions. When used as a flexible conductive substrate, it quickly restored the conductivity and enhanced the material's lifespan after surface damage. This environmentally friendly and self-healing waterborne PU elastomer will hold broad application prospects in the field of flexible electronic devices.

Nanocellulose/carbon nanotube/manganese dioxide composite electrodes with high mass loadings for flexible supercapacitors

The increasing commercialization of flexible electronic products has sparked a rising interest in flexible wearable energy storage devices. Supercapacitors are positioned as one of the systems with the most potential due to their distinctive advantages: high power density, rapid charge and discharge rates, and long cycle life. However, electrode materials face challenges in providing excellent mechanical strength while ensuring sufficient energy density. This study presents a method for constructing a flexible composite electrode material with high capacitance and mechanical performance by electrochemically depositing high-quality manganese dioxide (MnO2) onto the surface of a nanocellulose (CNF) and carbon nanotube (CNT) conductive film. In this electrode material, the CNF/CNT composite film serves as a flexible conductive substrate, offering excellent mechanical properties (modulus of 3.3 GPa), conductivity (55 S/cm), and numerous active sites. Furthermore, at the interface between MnO2 and the CNF/CNT substrate, C-O-Mn bonds are formed, promoting a tight connection between the composite materials. The assembled symmetric flexible supercapacitor (FSC) demonstrates impressive performance, with an areal specific capacitance of 934 mF/cm2, an energy density of 43.10 Wh/kg, a power density of 166.67 W/kg and a long cycle life (85 % Capacitance retention after 10,000 cycles), suggesting that they hold promise for FSC applications.

Ionogels for flexible conductive substrates and their application in biosensing

Ionogels are highly conductive gels made from ionic liquids dispersed in a matrix made of organic or inorganic materials. Ionogels are known for high ionic conductivity, flexibility, high thermal and electrochemical stability. These characteristics make them suitable for sensing and biosensing applications. This review discusses about the two main constituents, ionic liquids and matrix, used to make ionogels and effect of these materials on the characteristics of ionogels. Here, the material properties like mechanical, electrochemical and stability are discussed for both polymer matrix and ionic liquid. We have briefly described about the fabrication methods like 3D printing, sol-gel, blade coating, spin coating, aerosol jet printing etc., used to make films or coating of these ionogels. The advantages and disadvantages of each method are also briefly summarized. Finally, the last section provides a few examples of application of flexible ionogels in areas like wearables, human-machine interface, electronic skin and detection of biological molecules.

Low-Temperature Fabrication of Flexible Dye-Sensitized Solar Cells: Influence of Electrolyte Solution on Performance under Solar and Indoor Illumination

Flexible photovoltaics is an attractive technology for product-integrated energy supply under both outdoor and interior conditions. In particular, dye-sensitized solar cells (DSSCs) based on flexible plastic conductive substrates provide ample opportunities for unique applications; however, they prevent the use of high-temperature processing steps usually applied in the fabrication of the solar cell. In the first part of this paper, we present an overview of a careful selection of the most relevant work in the field of flexible DSSCs (F-DSSCs), ranging from pioneering methodsto the most cutting-edge techniques. Key elements and critical considerations for the design of an efficient F-DSSC are also provided. In the second part, we report the fabrication of DSSCs on both rigid and flexible plastic substrates using low-temperature processing. Three different I−/I3− electrolyte configurations were tested. Rigid and F-DSSC showed 2.62% and 1.00% efficiency under 1 sun and an output power of 8.60 and 4.00 μW/cm−2 under low-light conditions, respectively. In this work, we report a novel solvent mixture that shows a significant enhancement of the performance of the low-temperature processed configuration, without adding steps in the fabrication process.

Robust conductive polymer grafted carbon cloth via solvothermal polymerization for flexible electrochemical devices

Flexible electrodes have been widely investigated in wearable electronic devices, which cycling stability and flexibility are determined by the flexible conductive substrates, electroactive materials, and their interfaces. Here, a conductive polymer with superior chemical and structural stability, poly(1,5-diaminoanthraquinone) (PDAA), has been grafted onto the oxidized carbon cloth (OCC) via highly efficiently solvothermal polymerization. The robust PDAA grafted carbon cloth (OCC-PDAA) was obtained as flexible electrode for supercapacitors, possessing a capacitance of 386.3 mF cm−2, power density of 188.0 mW cm−2 and energy density of 34.4 mWh cm−2 at 0.50 mA cm−2, with superior capacitance retention of 99.1% and 96.5% after 10000 CV cycles and 180°-bending for 300 cycles, respectively. Such superior comprehensive electrochemical performance makes it a promising candidate for practical application.

Citric acid modified semi-embedded silver nanowires/colorless polyimide transparent conductive substrates for efficient flexible perovskite solar cells.

Flexible solar cells, with the merits of structure compactness and shape transformation, are promising power sources for future electronic devices. However, frangible indium tin oxide-based transparent conductive substrates severely limit the flexibility of solar cells. Herein, we develop a flexible transparent conductive substrate of silver nanowires semi-embedded in colorless polyimide (denoted as AgNWs/cPI) via a simple and effective substrate transfer method. A homogeneous and well-connected AgNW conductive network can be constructed through modulating the silver nanowire suspension with citric acid. As a result, the prepared AgNWs/cPI shows low sheet resistance of about 21.3 ohm sq.-1, high transmittance at 550 nm of 94%, and smooth morphology with the peak-to-valley roughness value of 6.5 nm. The perovskite solar cells (PSCs) on AgNWs/cPI exhibit power conversion efficiency of 14.98% with negligible hysteresis. Moreover, the fabricated PSCs maintain nearly 90% initial efficiency after bending for 2000 cycles. This study sheds light on the importance of suspension modification for the distribution and connection of AgNWs and paves a way for the development of high-performance flexible PSCs for practical applications.

Robust mica perovskite photoelectric resistive switching memory

Metal halide perovskites have attracted considerable attention for use in flexible resistive random access memory (RRAM), due to their good photoelectric regulation, high ON/OFF ratios, and low fabrication costs. Flexible conductive substrates play a crucial role in improving RRAM device performance. Herein, mica/silver nanowires welded with aluminum-doped zinc oxide (mica/AgNWs@AZO) substrates with high-temperature resistance, high flexibility, high conductivity, and good stability have been successfully fabricated. The average sheet resistance 3.5 Ω sq−1 of the conductive mica substrate is 68% lower than that of a commercial PET/ITO, and it remains stable below 13.1 Ω sq−1 under 200 °C. The maximum conductivity of the mica/AgNWs@AZO substrate can reach 58 S/m after 64 h of tensile stress bending at a radius of 20 mm. Perovskite CsPbBr3 nanocrystal (NC) RRAM is constructed on the mica/AgNWs@AZO substrate. The ON/OFF ratio 103 of the device in light is 102 times higher than that in dark under 5000 bending cycles. Flexible perovskite RRAM is a promising candidate for next-generation-logic, adaptive, non-volatile memory devices.

Novel metallic stainless-steel mesh-supported conductive membrane and its performance in the electro-filtration process

In this study, we demonstrate the fabrication of a thoroughly metallic electro-conductive membrane by using simple filtration to uniformly coat AgNWs dispersion through stainless steel (SUS)-mesh, which functions both as filter and a flexible conductive substrate. The as-prepared AgNWs networks layer on the SUS-mesh was further strengthened by electroplating Ag layers (P-SUS membrane); exhibiting an overall electrical conductivity of 9.2 × 104 S/m, which is up to 42 times greater than the conductivity of pristine SUS-mesh. The P-SUS membrane exhibited adequate physical durability against chemical and mechanical stresses under prolonged filtration, and high pure water flux of 534 ± 54 LMH/bar. This electro-membrane displayed the anticipated flux recovery in harvesting microalgae (Chlorella sp. HS-2) when filtration was done with the membrane used as a cathode: micro-sized bubbles, generated from the cathodic membrane, functioned to detach the foulants and recover the relative flux to a significant level. The P-SUS membrane indeed possesses necessary traits that the polymer-support membrane lacks, in terms of not only electrical conductivity and mechanical strength but also filtration performance with anti-fouling capability, all of which are of necessity to be considered workable electroconductive membrane.

Passivation of perovskite layer surface states with pyridine in flexible and printed perovskite solar cells

Perovskite solar cells (PSCs), prepared by using solution-processed printing techniques, gained much attention over the past few years and a considerable progress has been achieved in improving the power conversion efficiencies of these devices. Nevertheless, there are still some advancements that can be implemented, especially in terms of passivation of surface defects in the perovskite photoactive layer. Passivation can afford considerable reduction in surface recombination of charge carriers in the photoactive layer and help to obtain devices with better performance. In this work, poly(3-hexylthiophene-2,5-diyl)-based inks with small amount of pyridine as an additive are used to deposit the hole transport layer and simultaneously passivate the surface defects of the perovskite layer in flexible and printed PSCs. The devices are fabricated on flexible conductive plastic substrates using a slot-die coating method. It is found that 2.5 wt.% pyridine-containing inks for preparing hole transport layer have a positive effect on the performance of resulting PSCs. On average, around 13% improvement in the power conversion efficiency is observed for the devices with passivation as opposed to the reference devices without passivation. The effect of pyridine passivation on the structural and electronic properties of the perovskite layer on a flexible substrate is studied using experimental and analytical techniques, whereas the computer simulation methods are employed to rule out the possible mechanisms for the performance improvements in the devices with passivation. The approach presented here can be useful for developing simplified protocols for printing of flexible PSCs with the passivated perovskite layer and improved device efficiency.

Swelling-reconstructed chitosan-viscose nonwoven fabric for high-performance quasi-solid-state supercapacitors

Fabrics are often used as freestanding substrates for energy storage devices owing to their hierarchical porous structure and excellent mechanical flexibility. However, it is still a challenge to achieve a high loading mass of electroactive materials for outstanding electrochemical performance. In this work, with the help of high swelling property of chitosan, the chitosan-viscose nonwoven fabric (CVF) is successfully reconstructed to expand its specific surface area for flexible conductive substrates in the supercapacitors. Then, multi-walled carbon nanotubes (MWCNTs) are coated on the surface of crosslinked chitosan-viscose nonwoven fabric (c-CVF) to form the conductive framework. Subsequently, polypyrrole (PPy) is deposited by in-situ interfacial polymerization on the above conductive MWCNT/c-CVF substrate. The optimized PPy/MWCNT/c-CVF composite electrode shows not only a high electrical conductivity of 285.9 ± 1.2 S·cm−1, but also a prominent specific capacitance of 10112.9 mF·cm−2 at 2 mA·cm−2. Moreover, the prepared composite electrode also exhibits a high flexibility and good rate capability, in which the 70.3% capacitance is retained when the current density increases from 2 mA·cm−2 to 10 mA·cm−2. Besides, the quasi-solid-state symmetric supercapacitor, being assembled with the optimized composite fabric electrodes, produces the maximum areal specific capacitance of 1748.0 mF·cm−2 at 2 mA·cm−2 and the outstanding energy density of 155.4 μWh·cm−2 at a power density of 0.88 mW·cm−2. This work provides an effective approach to reconstruct the blended nonwoven fabric structure for high-performance flexible conductive substrate in the supercapacitors.

Free-standing Si3N4 nanowires@pyrolytic carbon membranes decorated with metal oxide nanoarrays for flexible hybrid supercapacitors

To satisfy the increasing requirement of flexible energy storage devices, various free-standing flexible conductive substrates were developed to construct high-performance supercapacitor electrodes. In this work, free-standing, flexible and conductive Si3N4 nanowires (NWs)@pyrolytic carbon (PyC) membrane, served as nanoscale substrate, was fabricated by a two-step chemical vapor deposition (CVD) method. NiCo2O4 nanosheets (NSs) and Fe2O3 nanorods (NRs) were finally grown on Si3N4NWs@PyC membrane substrates, which were directly served as the positive and negative electrodes, respectively. The membrane electrodes possesss the structural advantages, such as the interwoven network structure of nanowires substrates and array structure of active materials, which guarantee the excellent electrochemical performance of electrodes. Additionally, the flexible solid-state hybrid supercapacitor (HSC) assembled by Si3N4NWs@PyC@NiCo2O4NSs and Si3N4NWs@PyC@Fe2O3NRs, delivered a high energy density of 74.3 Wh kg−1 at a power density of 0.8 kW kg−1, excellent cycling stability (Capacitance retention of 84.6% after 4000 cycles), and good flexibility. Impressively, this work provides a new thinking about the structural design of high-performance supercapacitor electrodes as well as expands the application field of ceramic nanowires macrostructures.

Growth of Nanostructured Zinc Oxide on Flexible Conductive Substrate: A Review

In this paper, a review on the structural and morphological of nanostructured zinc oxide (ZnO) fabricated on flexible conductive substrate, mainly indium tin oxide coated on polyethylene terephthalate (ITO/PET) via various fabrication method is reported. Besides fabrication method, the effect of fabrication condition such as immersion time of ZnO-ITO/PET via hydrothermal method, concentration of modification material of precursor solution via sol-gel method, value of applied cathodic voltage and value of current densities via electrochemical deposition are also discussed. XRD analysis showed that the growth of ZnO-ITO/PET are preferred on (002) or (101) planes. SEM analysis revealed various type of nanostructured ZnO when prepared by sol-gel, spin coating, HWT and hydrothermal method, highlighting ZnO nanorods as the main morphology of ZnO-ITO/PET. The diameter of ZnO nanorods ranges from 10 nm to 830 nm.

3D hetero-nanostructured electrode constructed on carbon fiber paper with 2D 1T-MoS2/1D Cu(OH)2 for flexible asymmetric solid-state supercapacitors

One-dimensional Cu(OH)2 nanorods and two-dimensional 1T-MoS2 nanosheets have attracted attention due to their attractive electrochemical properties. However, 1T-MoS2 nanosheets tend to agglomerate and transform to 2H-MoS2, resulting in a decrease in electrochemical performance. In this study, flexible electrodes with 3D hetero-nanostructures are constructed by growing Cu(OH)2 nanorod arrays and loading 1T-MoS2 nanosheets on carbon fiber paper made of chopped carbon fibers as a conductive flexible substrate. The flower-shaped 1T-MoS2 nanosheets with increased interlayer spacing are conducive to the rapid diffusion and insertion of electrolyte, while the conductive copper hydroxide nanorod array and carbon fiber paper can facilitate electron transport. The 1T-MoS2/Cu(OH)2@CFP based electrode has a high areal capacitance of 1124.0 mF cm−2 at 1 mA cm−2 and excellent cycle stability (with 98.3% capacitance retention after 10000 charge-discharge cycles). Furthermore, a flexible asymmetric solid-state supercapacitor (FASSC) device based on the as-prepared 1T-MoS2/Cu(OH)2@CFP electrode exhibits an energy density of 0.130 mWh cm−2 at a power density of 0.375 mW cm−2. The capacitance of FASSC device remains 90.8% of the initial value after 20000 cycles. In addition, the CFP substrate can be bent at a large angle and folded into different shapes, which makes 1T-MoS2/Cu(OH)2@CFP based electrodes suitable for flexible and portable electronics.

High effective sensitivity, wide working range of melt-blown nonwoven conductive substrates for smart wearable strain sensors

High sensitivity, wide working range and flexible portability of strain sensors are crucial for smart wearable applications. To obtain these performances, several elastic melt-blown nonwoven substrates with excellent flexibility and high conductivity were developed by loading with polypyrrole through a double-dipping and double-rolling finishing method. The structure and conductivity are characterized by scanning electron microscope, infrared spectrometer, digital source meter and so on. The results indicate that the conductivity of prepared substrates is affected by the pyrrole concentration and polypyrrole amount deposited in nonwovens. Obviously, the conductivity and sensitivity of substrates as strain sensors are highly and positively correlated to the fiber orientation in nonwovens, and the effective working range and corresponding sensitivity of sensors are determined by the elastic deformation interval of melt-blown substrate. When the pyrrole concentration is 5.5%, the nonwoven substrate with 45.30% porosity possesses the anisotropic optimal conductivity with 23.491 S m−1 along winding direction and 15.063 S m−1 along width direction. Moreover, the as-prepared flexible conductive substrate exhibits the characteristics of wide working strain range (0%–24.2%), high sensitivity with 1.94 gauge factor at the range, fast response (0.023 s), tiny hysteresis (0.011 s), high durability and stability after 1000 cycles. Furthermore, the as-prepared sensor provides an effective method to prepare smart wearable strain sensors used as the monitor of finger bending in details and the precise recognition of human voice changes.

In-situ electrochemical polymerization of aniline on flexible conductive substrates for supercapacitors and non-enzymatic ascorbic acid sensors

Polyaniline, as a kind of conductive polymer with commercial application prospects, is still under researches in its synthesis and applications. In this work, polyaniline was fabricated on flexible substrates including carbon cloths and polyethylene naphthalate by in situ electropolymerization method. The synthesized flexible electrodes were characterized by scanning electron microscopy, High resolution transmission electron microscope, atomic force microscope, Fourier transform infrared, x-ray diffraction, and x-ray photoelectron spectroscopy. Owing to the conductivity and the reversible redox property, the polyaniline/carbon cloth electrodes show excellent properties such as decent supercapacitor performance and good detection capability toward ascorbic acid. As supercapacitors, the electrodes exhibit a specific capacitance as high as 776 F g–1 at a current density of 1 A g–1 and a long cycle life of 20 000 times in the three-electrode system. As ascorbic acid sensors, the flexible electrodes demonstrate stable response to ascorbic acid in the range of 1–3000 μM with an outstanding sensitivity (4228 μA mM–1 cm–2), low detection limit (1 μM), and a fast response time. This work holds promise for high-performance and low-cost flexible electrodes for both supercapacitors and non-enzymatic ascorbic acid sensors, and may inspire inventions of self-powered electrochemical sensor.

Highly conductive organic-ionogels with excellent hydrophobicity and flame resistance

Very different from electronic conductors, ionic conductors usually possess some unique functions such as stretchability, transparency and ionic conductivity, thus exhibiting a great promise in the flexible wearable electronic devices. Herein, we develop a novel stretchable transparent organic-ionogel (OIG-TBP-50) via a rapid photo-curing process, in which we select the mixture of tributyl phosphate (TBP) and 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)amine ([BMMIm][NTf2]) as fireproof and conductive solvent, respectively. Just benefiting from the good synergistic effect of TBP and [BMMIm][NTf2], our-designed OIGs demonstrate excellent hydrophobicity and flame resistance as well as perfect stretchability (757%), high transparency (93%) in visible region, good environmental stability, wide temperature tolerance range (from −55 °C to 180 °C) and high ionic conductivity (1.73 × 10-3 S cm−1 at room temperature). In addition, our stretchable transparent OIGs even could light LED lamps under an alternating current field when directly used as the flexible conductive substrate. Further applying such OIGs as ionic conductor to assemble flexible sensor and touch screen, both of them could transport rapid signal response under slight touch stress.

Curved-Mechanical Characteristic Measurements of Transparent Conductive Film-Coated Polymer Substrates Using Common-Path Optical Interferometry

This study proposes a method for measuring curved-mechanical characteristics based on a whole-folding test for transparent conductive film-coated polymer substrates using common-path optical interferometry. Accordingly, 80-, 160-, and 230-nm indium tin oxide films coated on 40 × 40 mm 125-μm-thick polyethylene terephthalate (PET) substrates, and monolayer graphene films coated on 40 × 40 mm 250-μm-thick PET substrates are inspected and analyzed under the curving conditions of 50-, 30-, 20-, and 10-mm radii before and after an 11,000 whole-folding cycle test based on a 10-mm folding radius. This study utilizes the changes in the phase retardations of transparent conductive film-coated polymer substrates under different curving conditions before and after 11,000 whole-folding cycles to analyze the substrates’ residual stress characteristics that were the direct result of manufacturing process parameters. The results from this study of curved-mechanical characteristic measurements of flexible transparent conductive substrates can provide designers with improved product development and can assist manufacturers in improving the manufacturing design of enhanced coating processes.