Carbon Nanotube Nanofiber Research Articles

Multifunctional Janus-Structured Polytetrafluoroethylene-Carbon Nanotube-Fe3O4/MXene Membranes for Enhanced EMI Shielding and Thermal Management.

Herein, a novel Janus-structured multifunctional membrane with integrated electromagnetic interference (EMI) shielding and personalized thermal management is fabricated using shear-induced in situ fibrillation and vacuum-assisted filtration. Interestingly, within the polytetrafluoroethylene (PTFE)-carbon nanotube (CNT)-Fe3O4 layer (FCFe), CNT nanofibers interweave with PTFE fibers to form a stable "silk-like" structure that effectively captures Fe3O4 particles. By incorporating a highly conductive MXene layer, the FCFe/MXene (FCFe/M) membrane exhibits excellent electrical/thermal conductivity, mechanical properties, and flame retardancy. Impressively, benefiting from the rational regulation of component proportions and the design of a Janus structure, the FCFe/M membrane with a thickness of only 84.9µm delivers outstanding EMI shielding effectiveness of 44.56dB in the X-band, with a normalized specific SE reaching 10,421.3dB cm2g-1, which is attributed to the "absorption-reflection-reabsorption" mechanism. Furthermore, the membrane demonstrates low-voltage-driven Joule heating and fast-response photothermal performance. Under the stimulation of a 3V voltage and an optical power density of 320mW cm-2, the surface temperatures of the FCFe/M membranes can reach up to 140.4 and 145.7°C, respectively. In brief, the FCFe/M membrane with anti-electromagnetic radiation and temperature regulation is an attractive candidate for the next generation of wearable electronics, EMI compatibility, visual heating, thermotherapy, and military and aerospace applications.

A high-performance, flexible, and dual-modal humidity-piezoelectric sensor without mutual interference

High-performance, flexible, and multifunctional humidity-piezoelectric sensors are applicable to respiratory pattern detection, man-machine motion distinction, and dual-modal speech recognition. However, signal disturbances between the humidity and pressure signals remain, and interference from the external environment such as temperature further results in signal vibrations. In this study, a high-performance, flexible, and dual-modal humidity-piezoelectric sensor is introduced to achieve accurate and stable sensing signals by fully prohibiting mutual interference towards simultaneous humidity and pressure stimuli. It is first designed using a high-performance humidity-sensing unit constructed by polyacrylate sodium (PAAS)/carbon nanotube (CNT) film and a piezoelectric sensing unit formed by polyvinylidene fluoride (PVDF)/CNT nanofiber film. The patterned PAAS/CNT unit exhibits a resistance change of 1100 % in relative humidity of 23 %–98 %, minor hysteresis, favorable durability, and negligible pressure interference. The PVDF/CNT piezoelectric unit demonstrates a sensitivity of 0.11 V/kPa in a wide pressure range of 3–115 kPa, good linearity, high durability, negligible humidity and temperature interference, and fully prohibited signal noise. Moreover, the high-performance, flexible, dual-modal humidity-piezoelectric sensors display significant applications for man-machine motion detection, human gestures and object distinction, and dual-modal speech recognition.

Highly Flexible Electrodes Based on Nano/Micro‐Fiber for Flexible Lithium Metal Batteries

AbstractAlthough Li metal batteries (LMBs) with high flexibility are attractive energy storage systems for wearable devices due to their high energy density, there exist critical challenges such as limited loading density, poor dimensional stability, and thus mechanical instability under repeated mechanical deformations including bending, twisting, and folding. In this work, extremely flexible nano/microfiber composite electrodes are developed for LMBs. The highly flexible and mechanically durable electrode is composed of oxidized polyethylene terephthalate (O‐PET) microfiber (MF) substrates covered by single‐walled carbon nanotube (CNT) nanofibers (NF), prepared by mass‐producible O2 plasma treatment and spray‐coating. CNT nanofibers provided an electrical intertangled network to integrate the active materials (i.e., either NCM or passivated Li powder (PLP)) and anchored to a flexible O‐PET MF substrate, which permits high mass loading of active materials, improved electrochemical performance while maintaining mechanical durability. Resultantly, the flexible LMBs based on nano/micro fibrous electrodes have excellent energy density (300.1 Wh kg−1 electrode; nominal voltage of 3.7 V) and stable capacity retention (97.1%) without mechanical failure over 500 folding cycles.

In silico studies and development of a protein-based electrochemical sensor for selective and sensitive detection of aflatoxin B1.

Proteins from different species have been dockedwith aflatoxin B1 (AFB1) and identified 3 proteins (prostaglandin-E(2)9-reductase from Oryctolagus uniculus, proto-oncogene serine/threonine-protein kinase Pim-1 and human immunoglobulin G (hIgG)) as potential candidates to develop an electrochemical sensor. Fluorescence spectroscopy experiments have confirmed the interaction of hIgG with AFB1 with an affinity constant of 4.6 × 105 M-1. As a proof-of-concept, hIgG was immobilized on carbon nanocomposite (carbon nanotube-nanofiber, CNT-F)-coated glassy carbon electrode (GCE). FT-IR spectra, HR-TEM and BCA assay have confirmed successful immobilization of hIgG on the electrode (hIgG@CNT-F/GCE). The preparation of this protein electrochemical sensor requires only 1h 36min, which is fast as compared withpreparing an electro immunosensor. hIgG@CNT-F/GCE has displayed an excellent AFB1 limit of detection (0.1 ng/mL), commendable selectivity in the presence of two other mycotoxins (ochratoxin A and patulin) andthe detection of AFB1 in spikedpeanuts and corn samples.

Integration of Functional Human Auditory Neural Circuits Based on a 3D Carbon Nanotube System.

The physiological interactions between the peripheral and central auditory systems are crucial for auditory information transmission and perception, while reliable models for auditory neural circuits are currently lacking. To address this issue, mouse and human neural pathways are generated by utilizing a carbon nanotube nanofiber system. The super-aligned pattern of the scaffold renders the axons of the bipolar and multipolar neurons extending in a parallel direction. In addition, the electrical conductivity of the scaffold maintains the electrophysiological activity of the primary mouse auditory neurons. The mouse and human primary neurons from peripheral and central auditory units in the system are then co-cultured and showed that the two kinds of neurons form synaptic connections. Moreover, neural progenitor cells of the cochlea and auditory cortex are derived from human embryos to generate region-specific organoids and these organoids are assembled in the nanofiber-combined 3D system. Using optogenetic stimulation, calcium imaging, and electrophysiological recording, it is revealed that functional synaptic connections are formed between peripheral neurons and central neurons, as evidenced by calcium spiking and postsynaptic currents. The auditory circuit model will enable the study of the auditory neural pathway and advance the search for treatment strategies for disorders of neuronal connectivity in sensorineural hearing loss.

Ultrathin silk nanofiber-carbon nanotube skin tattoos for wirelessly triggered and temperature feedbacked transdermal drug delivery.

The online version contains supplementary material available at 10.1007/s13534-024-00363-6.

Role of Electrical Conductivity in the Shielding Effectiveness of Composite Polyvinyl Alcohol/Multiwall Carbon Nanotube Nanofibers for Electromagnetic Interference Applications.

The shielding effectiveness (SE) against the electromagnetic interference (EMI) of polyvinyl alcohol/multiwall carbon nanotubes (PVA/MWCNTs) composite nanofibers is characteristic of higher absorptivity of the radiation that enhances with the increasing concentration of MWCNTs content in these composites. However, by enriching the content of conductive fillers (MWCNTs), the conductivity of the composites is also stirred up. Concomitantly, the conductivity of these composites contributes toward the reflectivity of the EM radiation from them. Certain applications of the EMI shielding material require a lower level of reflectivity of the EM radiation. This study intends to see how SE of the PVA/MWCNTs composite nanofibers is affected vis-a-vis their conductivity for S-band radiation. Samples of nanofibers, with (5, 10, 15, and 20) wt % of MWCNTs loading in 10 wt % of PVA solution, were prepared through electrospinning and studied for their electrical conductivity and EMI SE. It is observed that by increasing the content of MWCNTs in PVA solution from 5 to 20 wt % the conductivity of the composites tends to increase from 21 to 866 times that of PVA, while the SE increases from 10 db to 25 db over the S-band range of frequencies.

Superb Bifunctional Water Electrolysis Activities of Carbon Nanotube-Decorated Lanthanum Hydroxide Nanocomposites

For highly efficient hydrogen production from electrocatalytic water electrolysis, developing a high-fidelity electrocatalyst is pivotal. Herein, we demonstrated the excellent water-splitting performances of the carbon allotrope-decorated rare earth oxide nanocomposite system, which was composed of lanthanum hydroxide (La(OH)3) and carbon nanotube (CNT). The nanocomposites of CNT-La(OH)3 were fabricated via facile ultrasonication using La(OH)3 nanoparticles and CNT nanofibers, and they exhibited excellent bifunctional water-splitting activities. For the hydrogen evolution reaction, CNT-La(OH)3 showed low values of both overpotential (150 mV) and Tafel slope (113 mV/dec) in 1 M KOH at -10 mA/cm2. Additionally, for the oxygen evolution reaction, CNT-La(OH)3 also displayed small values for their overpotential (310 mV) as well as the Tafel slope (39 mV/dec). Furthermore, both bifunctional hydrogen- and oxygen-evolution reactions were confirmed to be stable in chronopotentiometric tests. From the material characterization and the electrochemical characterization, such excellent bifunctional water electrolysis performances were ascribed to the synergetic effects of hybridization of La(OH)3 (i.e., a large number of electrochemically active sites of 304 cm2) and CNT (i.e., high charge transport conductivity). The results specify that the present CNT-La(OH)3 nanocomposite system possesses ample aptitude as a superior electrocatalyst for next-generation hydrogen production technology.

Extrusion 3D printing of carbon nanotube-assembled carbon aerogel nanocomposites with high electrical conductivity

Carbon nanotubes (CNTs) with high aspect ratio and excellent electrical conduction offer huge functional improvements for current carbon aerogels. However, there remains a major challenge for achieving the on-demand shaping of carbon aerogels with tailored micro-nano structural textures and geometric features. Herein, a facile extrusion 3D printing strategy has been proposed for fabricating CNT-assembled carbon (CNT/C) aerogel nanocomposites through the extrusion printing of pseudoplastic carbomer-based inks, in which the stable dispersion of CNT nanofibers has been achieved relying on the high viscosity of carbomer microgels. After extrusion printing, the chemical solidification through polymerizing RF sols enables 3D-printed aerogel nanocomposites to display high shape fidelity in macroscopic geometries. Benefiting from the micro-nano scale assembly of CNT nanofiber networks and carbon nanoparticle networks in composite phases, 3D-printed CNT/C aerogels exhibit enhanced mechanical strength (fracture strength, 0.79 ​MPa) and typical porous structure characteristics, including low density (0.220 ​g ​cm−3), high surface area (298.4 ​m2 ​g−1), and concentrated pore diameter distribution (∼32.8 ​nm). More importantly, CNT nanofibers provide an efficient electron transport pathway, imparting 3D-printed CNT/C aerogel composites with a high electrical conductivity of 1.49 ​S ​cm−1. Our work would offer feasible guidelines for the design and fabrication of shape-dominated functional materials by additive manufacturing.

Highly sensitive detection of glucose via glucose oxidase immobilization onto conducting polymer-coated composite polyacrylonitrile nanofibers

Current study introduces composite polyacrylonitrile - multiwall carbon nanotubes nanofibers (PAN-MWCNTs NFs) coated with conducting polymers (polypyrrole (PPy) or poly(3,4-ethylenedioxythiophene) (PEDOT)) by chemical vapor deposition for efficient glucose detection. The potential of nanofibrous assemblies and nano-conducting elements in biosensing was explored as pre-processing of NFs with MWCNTs and post-processing with CPs were both employed. These ‘core-shell’ conducting NFs were further employed as platforms for glucose oxidase immobilization for enzymatic detection of glucose. The performance of the biosensors was closely correlated with the concentration of immobilized enzyme and with the type of conducting polymer. The biosensors showed high sensitivities of 92.94 and 81.72 µA/mM.cm−2 for (PAN-MWCNTs)/ PEDOT and (PAN-MWCNTs)/ PPy accompanied by low limit of detection values of 2.30 and 2.38 µM, respectively. Good operational stability was observed throughout twenty-five consecutive measurements, over 90% activity was maintained for both sensors. This study represents proof of concept for the methodology, showcasing the advantages of nanomaterial synthesis for bio-applications. The work was compared thoroughly with previously reported biosensors showing some of the best results reported to date in terms of analytical characteristics.

Designing carbon nanotube and nanofiber-polypropylene hybrid cementitious composites with improved pre- and post- crack load carrying and energy absorption capacity

This study reports recent developments on carbon nanotube (CNT), nanofiber (CNF), and polypropylene microfiber (PP) hybrid reinforced cementitious composites. Notable characteristics are (i) significantly enhanced load carrying capacity; and (ii) increased energy absorption capability at both elastic and post-first cracking stages. Three point bending tests on notched and unnotched specimens have shown that the addition of 0.3 vol% CNTs and CNFs in PP reinforced mortars increases the modulus of elasticity and first crack strength and toughness by 93%, 64% and 49% respectively. The experimental values perfectly agree with the theoretically determined modulus using a micromechanics-based model. Hybrid mixes showed considerable increase in toughness, exhibited toughness index values I5 of 4 or more, and 4 times higher residual strength. Relative to the PP microfiber reinforced mortar, the developed hybrid material is able to sustain a much higher load and successfully transfer tensile stresses across cracks, without losing its tensile load carrying capacity. Such exceptional mechanical behavior is an important performance factor for serviceability and is interpreted in terms of the mechanism of a synergistic interaction between the nano and micro scale fiber reinforcement.

Self-assembled cellulose nanofiber-carbon nanotube nanocomposite films with anisotropic conductivity.

In this study, a nanocellulose-based material showing anisotopic conductivity is introduced. The material has up to 1000 times higher conductivity along the dry-line boundary direction than along the radial direction. In addition to the material itself, the method to produce the material is novel and is based on the alignment of cationic cellulose nanofibers (c-CNFs) along the dry-line boundary of an evaporating droplet composed of c-CNFs in two forms and conductive multi-walled carbon nanotubes (MWCNTs). On the one hand, c-CNFs are used as a dispersant of MWCNTs, and on the other hand they are used as an additional suspension element to create the desired anisotropy. When the suspended c-CNF is left out, and the nanocomposite film is manufactured using the high energy sonicated c-CNF/MWCNT dispersion only, conductive anisotropy is not present but evenly conducting nanocomposite films are obtained. Therefore, we suggest that suspending additional c-CNFs in the c-CNF/MWCNT dispersion results in nanocomposite films with anisotropic conductivity. This is a new way to obtain nanocomposite films with substantial anisotropic conductivity.

Polymeric Nanofiber-Carbon Nanotube Composite Mats as Fast-Equilibrium Passive Samplers for Polar Organic Contaminants.

To improve the performance of polymeric electrospun nanofiber mats (ENMs) for equilibrium passive sampling applications in water, we integrated two types of multiwalled carbon nanotubes (CNTs; with and without surface carboxyl groups) into polyacrylonitrile (PAN) and polystyrene (PS) ENMs. For 11 polar and moderately hydrophobic compounds (-0.07 ≤ logKOW ≤ 3.13), 90% of equilibrium uptake was achieved in under 0.8 days (t90% values) in nonmixed ENM-CNT systems. Sorption capacity of ENM-CNTs was between 2- and 50-fold greater than pure polymer ENMs, with equilibrium partition coefficients (KENM-W values) ranging from 1.4 to 3.1 log units (L/kg) depending on polymer type (hydrophilic PAN or hydrophobic PS), CNT loading (i.e., values increased with weight percent (wt %) of CNTs), and CNT type (i.e., greater uptake with carboxylated CNTs composites). During field deployment at Muddy Creek in North Liberty, Iowa, optimal ENM-CNTs (PAN with 20 wt % carboxylated CNTs) yielded atrazine concentrations in surface water with a 40% difference relative to analysis of a same-day grab sample. We also observed a mean percent difference of 30 (±20)% when comparing ENM-CNT sampler results to grab sample data collected within 1 week of deployment. With their rapid, high capacity uptake and small material footprint, ENM-CNT equilibrium passive samplers represent a promising alternative to complement traditional integrative passive samplers while offering convenience over large volume grab sampling.

Impedance-Based Biosensing of Pseudomonas putida via Solution Blow Spun PLA: MWCNT Composite Nanofibers.

Quantifiable sensing of common microbes in chronic wounds has the potential to enable an objective assessment of wound healing for diagnostic applications. Sensing platforms should be robust, simple, and flexible to provide clinicians with a point-of-care tool. In this work, solution blow spun poly (lactic acid)/multiwalled carbon nanotube nanofiber composites are used to detect the presence and concentration of Pseudomonas putida in vitro using changes in impedance. Impedance microbiology (IM) is a well-documented diagnostic technique used in many applications, including cancer detection, tuberculosis screening and pregnancy tests. Twenty-four hour real-time measurements of the equivalent circuit of three culture media were taken with an inductance, capacitance, and resistance (LCR) meter. Variations in impedance were calculated to correspond to the growth of P. putida. Additionally, instantaneous measurements of bacterial cultures were taken over a one-minute time point to display the fast sensing of bacterial load via IM. This proof-of-concept shows that conductive solution blow spun fiber mats is a valid fabrication technique to develop in situ wound dressing impedance sensors. Study results indicate successful measurement and quantification of bacterial growth in this proof-of-concept study.

Flexible high-temperature sheet-type electric heaters using m-aramid/functionalized MWCNTs hybrid nanofiber composites

Poly(m-phenylene isophthalamide) (m-aramid)/functionalized multi-walled carbon nanotube nanofibers (m-aramid/MWCNT-OH NFs) are prepared by electrospinning of the blended m-aramid/MWCNT-OH mixtures with MWCNT-OH contents of 0.1–1.0 wt%. Afterwards, the MWCNT-OH solutions (0.1–1.0 mg ml−1) dispersed in ethanol are further infiltrated into m-aramid/MWCNT-OH NF substrate via a facile solution casting method to obtain MWCNT-OH coated m-aramid/MWCNT-OH NF composites (MWCNT@m-aramid/MWCNT-OH NF composites). FE-SEM analysis demonstrates that the MWCNT-OH is well coated on the m-aramid/MWCNT-OH NF substrate, depending on the MWCNT-OH contents. The sheet resistance of as-fabricated MWCNT-OH@m-aramid/MWCNT-OH NF composites decreases largely from 2845 Ω □−1 to 158 Ω □−1 with the increase of MWCNT-OH concentrations from 0.1 to 1.0 mg ml−1, due to the percolation threshold of MWCNT-OH in the MWCNT-OH@m-aramid/MWCNT-OH NF composites. Besides, the obtained composites are flexible and reveal excellent electric heating performance. The maximum temperature of the MWCNT-OH(1.0 wt%)@m-aramid/MWCNT-OH NF composites is attained ca. 157 °C with high electric heating efficiency of 10.4 ± 1.8 mW/°C at small quantities (0.23 mg cm−2) of MWCNT-OH, suggesting that the MWCNT-OH(1.0 wt%)@m-aramid/MWCNT-OH NF composites can be applied as a promising high-temperature flexible sheet-type electric heaters.

Electrospun imidazolium functionalized multiwalled carbon nanotube/ polysulfone inorganic-organic nanofibers for reinforced anion exchange membranes

Novel electrospun inorganic-organic nanofiber reinforced anion exchange membranes were developed by incorporating imidazolium functionalized multiwalled carbon nanotubes (FMWCNTs) into imidazolium functionalized polysulfone nanofibers via co-electrospinning. Under a high-voltage electrostatic field, FMWCNT inorganic nanofibers were able to align along the axis of the electrospun nanofibers, thereby solving the problem of easy agglomeration of FMWCNTs in cast-composite anion exchange membrane, synergistic with the polymer nanofibers to reinforce the membranes. Small angle x-ray suggests that ion clusters are more likely to aggregate in a co-electrospun composite membrane, indicating continuous and lower-energy-barrier pathways for hydroxide transport. As a result, composite electrospun membranes exhibit higher OH− conductivity and better single fuel cell performance. With an additive amount of 0.4 wt.%, hydroxide conductivity reaches a maximum value of 67.5 mS cm−1 (30 °C). However, the maximum power density (102.5 mWcm−2) is much higher than that of the electrospun (2.1 times) and cast (3.3 times) membranes without FMWCNTs. Fibration of polymer and alignment of multiwalled carbon nanotube nanofibers also greatly enhance the membrane strength. For fully hydrated membranes, tensile stress dramatically increases from 5.6 MPa for a cast membrane without FMWCNTs to 24.4 MPa for an electrospun membrane with 0.4 wt.% FMWCNTs addition. The strategy for co-electrospinning of imidazolium functionalized multiwalled carbon nanotubes/polysulfone presented in this work provides a way to enhance the organic-inorganic interface compatibility, and improve ionic conductivity and mechanical strength of anion exchange membrane simultaneously.

Enhanced direct electron transfer of redox protein based on multiporous SnO2 nanofiber-carbon nanotube nanocomposite and its application in biosensing

A novel third generation H2O2 biosensor is fabricated using multiporous SnO2 nanofiber/carbon nanotubes (CNTs) composite as a matrix for the immobilization of redox protein onto glassy carbon electrode. The multiporous nanofiber (MPNFs) of SnO2 is synthesized by electrospinning technique from the tin precursor. This nanofiber shows high surface area and good electrical conductivity. The SnO2 nanofiber/CNT composite increases the efficiency of biomolecule loading due to its high surface area. The morphology of the nanofiber has been evaluated by scanning electron microscopy (SEM). Cyclic Voltammetry and amperometry technique are employed to study and optimize the performance of the fabricated electrode. A direct electron transfer between the protein's redox centre and the glassy carbon electrode is established after fabrication of the electrode. The fabricated electrode shows excellent electrocatalytic reduction to H2O2. The catalysis currents increases linearly to the H2O2 concentration in a wide range of 1.0 10−6–1.4×10−4M and the lowest detection limit was 30nM (S/N=3). Moreover, the biosensor showed a rapid response to H2O2, a good stability and reproducibility.

Electrospun carbon nanofiber-carbon nanotubes composites coated with polyaniline with improved electrochemical properties for supercapacitors

The carbon nanofiber-carbon nanotube (CNF-CNT) composites were fabricated by simple electrospinning and carbonization of polyacrylonitrile (PAN)-CNT solution prepared by first sonicating and stirring the CNT in N, N-dimethylformamide (DMF) as solvent. Aniline monomer was then coated on the composite materials via in situ chemical polymerization to form CNF-CNT-PANI composite. The as-prepared samples were then characterized. Importantly, the dispersed CNTs in the CNF-CNT composites were crucial for the CNF-CNTs acting as supports for the CNF-CNT-PANI composites to attain high electrochemical properties. The composite electrode material is found to be used as effective electrode material for supercapacitors with specific capacitance as high as 1119 F g−1at 1 A g−1 compared to the bare CNF film with a specific capacitance of 278 F g−1. The composite electrode displaced excellent cyclic stability with retention of 98% even after 2000 cycles at a current density of 10 A g−1.

A three‐dimensional carbon nanotube–nanofiber composite foam for selective adsorption of oils and organic liquids

Carbon nanotubes (CNTs) have attracted tremendous research interest area as promising sorbent material due to the large surface area for adsorption, excellent mechanical and chemical properties. To practically employ CNTs as a potential commercial sorbent, it is essential to form loosely packed architecture of CNTs in 3D space. In recent years, a series of CNTs‐based composites have been fabricated. However, these composites showed a highly compact structure and/or junctions with uneven/excessive CNTs deposition, which significantly limit their performance as sorbents. Herein, we report the direct fabrication of three‐dimensional flower‐like CNTs‐nanofibers foams (3D CNTs‐NFs) by freeze‐drying aqueous solutions of electrospun poly‐acetonitrile (PAN) nanofibers and CNTs. As a result, fully expanded multiple layered CNTs nanosheets with sufficient large surface area could be successfully integrated within the 3D nano‐fibrous architecture. The 3D CNFs‐NFs showed excellent mechanical properties and adsorption capacities, which permit this kind of CNTs composite foam could be used in selective adsorption processes and environmental applications. POLYM. COMPOS., 39:E271–E277, 2018. © 2017 Society of Plastics Engineers

Electrospun Poly(lactic-co-glycolic acid)/Multiwalled Carbon Nanotube Nanofibers for Cardiac Tissue Engineering

Many conductive scaffolds were fabricated to mimic the topography of the cardiac microenvironment in vitro in order to improve the performance of engineered cardiac tissues. This study fabricated aligned poly(lactic-co-glycolic acid)/multiwalled carbon nanotube fibers by electrospinning. The Young's modulus and conductivity were significantly greater on poly(lactic-co-glycolic acid) fibers with 3% multiwalled carbon nanotubes compared to others. Topographical cues and conductivity were applied to investigate the combined effect on cardiomyocyte behavior. Neonatal rat cardiomyocytes cultured on the conductive fibers maintained their viability, induced cell elongation, and enhanced sarcomeric α-actinin and troponin I production in cardiomyocytes. The results indicate that poly(lactic-co-glycolic acid)/multiwalled carbon nanotube composite fibers have great potential for cardiac tissue engineering.