In this study, using three types of resins (each with unique material properties) as a matrix, and carbon black (CB) as a conductive additive, conductive fibres were fabricated through a melt-spinning process. An examination of the electrical conductivity revealed that a CB/polyethylene terephthalate (PET) composite had a low percolation value of 0.58 wt%, and thus the highest conductivity of the three resin types. These results indicate that CB/PET fibres could be used to manufacture antistatic fabrics.

The present study deals with the potential application of chitosan nonwoven for biomedical textiles based on enzyme immobilization. For this, chitosan nonwoven was first cross-linked with glutaraldehyde to introduce aldehyde groups at optimal conditions. To immobilize the enzyme trypsin onto glutaraldehyde-pre-activated chitosan nonwoven, several parameters such as pH, enzyme concentration, and reaction times were investigated. In addition, the pH, thermal stability, storage stability, and reusability of immobilized trypsin were examined. We found that the optimal immobilization conditions for trypsin were pH 8.5, enzyme concentration of 8% (owf), and treatment time of 30 min. Trypsin was immobilized at 25 °C efficiently. The immobilized trypsin showed lower pH stability and better thermal stability than free trypsin. The immobilized trypsin showed 50% of its initial activity after being used 15 times and 80% of that after 20 days of storage at 4 °C. SEM analysis also confirmed that trypsin was immobilized on chitosan nonwoven.

Wearable biosensors have received significant attention due to the possibility of measuring physiological signals on demand. Particularly, the monitoring of electromyographic (EMG) signals on demand by wearable platforms has significant potential to revolutionize the diagnostics and treatment of neuromuscular diseases and for advancing human–computer interfaces. Electronic textile-based biosensors have several advantages, including the simple scale-up process and the ease of fabricating multiple large area electrodes over the whole body to obtain precise measurements. Hence, the electronic textile production requires an affordable approach to fabricate biocompatible and biostable electronic circuits on textile materials. This work explores the possibility of combining screen printing and electrodeposition techniques to produce a biostable nanocomposite-based EMG biosensor on textile. Screen printing was selected to fabricate conductive fabrics that would ultimately be a highly durable textile-based sensor. Silver paste, including microscale silver flakes, was printed on PET/cotton blended fabrics. However, the microscale silver surface was limited for EMG sensors due to low surface area and toxicity, causing low signal detection performance and skin irritation. Gold nanoparticles (Au NPs) were deposited on silver flakes to address the requirements of high-performance and biocompatible biosensors. We confirmed that the gold functionalization improved electrical and electrochemical performance. In addition, various tests were performed to determine electrochemical and biological stability under physiological conditions. The test results proved that Au NPs have successfully encapsulated the surface of silver flakes, preventing the exposure of the silver to the physiological environment. EMG signal recording was performed to confirm the functionalization effect that improved the signal to noise ratio (SNR) of 12.5 with 120 nm Au NPs. Moreover, EMG sensing from bicep workouts and finger movements showed the high sensitivity of the electronic fabrics. Although the SNR of EMG signals dropped to 7.2 after a 15-time washing test, the stabilized SNR after 5 washing cycles indicated that the Au/Ag biosensors showed washing durability. The study demonstrates that this affordable approach can be considered for large-scale production of wearable EMG biosensors.

A comparative study of the electrical performance of triboelectric nanogenerators (TENGs) with plain- and 2/1 twill-woven cotton textiles was conducted. Furthermore, the microstructures of the cotton fiber surfaces were examined to understand the fundamental mechanical interaction among the cotton fibers in the TENGs. The TENG with 2/1 twill-woven cotton textiles exhibited higher output voltages compared to that with plain-woven cotton textiles. The difference in the output voltage between the two types of TENGs resulted from the difference in triboelectric charge generation between the constituent cotton textiles. The higher output voltage of the TENG with 2/1 twill-woven cotton textiles was attributed to the higher density in triboelectric interactions among the cotton fiber molecules.

Polylactic acid (PLA) has received considerable attention as a biomass material in the textile industry. To use PLA fiber in the textile industry, suitable post-processing is needed. To establish enzymatic finishing of PLA fibers, we evaluated the hydrolytic activities of two representative lipolytic enzymes; lipase and esterase. In addition, we established the optimal hydrolytic treatment conditions of each enzyme. Results showed that the optimal lipase and esterase treatment conditions are a pH of 8.0, a temperature of 40°C, a concentration of 10% owf, and a calcium chloride concentration of 10 mM. PLA fabrics experienced a weight loss of about 0.7% from enzyme treatment with no loss of tensile strength. Biodeterioration due to enzymatic hydrolysis were observed in scanning electron microscopy images. There was an approximately twofold improvement in moisture regain by enzymatic hydrolysis. Finally, X-ray diffractometry identified a new peak localized at 2θ = 18.5° after enzyme treatment. The degree of crystallinity was increased and the crystallite size was decreased.