Smart clothes can be described as textiles that change their behavior under some external factors (stimulants). The response of the smart cloth can be passive (just as a sensor) or active (where a combination of sensing and another reaction takes place). The materials involved in these textiles are crucial for many applications, especially for health related applications where the “wearables” can provide instantaneous monitoring and aid to people with certain disabilities. This work consists of two main parts: First it investigates the different materials used in smart clothing for monitoring the vital activities of the human body (e.g. the breathing rates) with an emphasis on piezoresistive structures as they work sensing elements for mechanical strains. Second this work presents the production of functional membrane samples based on synthesized pyrrolinone ester hydrazone dye with a preliminary investigation of their chemical and geometrical parameters, especially their sensitivity for monitoring the presence of ammonia to function as a smart textile based colorimetric chemosensor.

There is a growing public interest in utilizing biomass and biomaterials to obtain products with high sustainability and less harm to the environment. This study reports on using electrospinning technique to produce nanofiber membranes based on homogeneous polymeric blends of gum Arabic, polyvinyl alcohol, and silver nanoparticles. The produced interconnected membranes were cross-linked via heat and plasma treatments, and the membranes were characterized for their chemical and physical characteristics. Fourier transform infrared spectroscopy shows a cross-linking of gum Arabic and polyvinyl alcohol through esterification during the heat treatment, and through graft polymerization with methyl groups after methane plasma treatment. The mechanical performance of the membranes showed an increase in the modulus of elasticity in the longitudinal direction (parallel to electrospun nanofibers) from 85 ± 4 MPa to 148 ± 5 MPa compared with the transverse direction. Also, well-dispersed nanoparticles in the spinning solution tend to increase the elasticity from 41 ± 3 MPa to 148 ± 5 MPa, while the agglomeration of these nanoparticles decreases the mechanical properties of the nanofibers. Results of the biodegradation tests confirmed the significant biodegradable nature of the produced nanofibers, where 99.09% of the material was degraded within 28 days. Moreover, samples showed significant bactericidal activity against Micrococcus luteus with significantly less-observed bacteria in the measured plate, while the inhibition zone for Escherichia coli was 1 cm. The produced biodegradable electrospun membranes have multiple potential applications in many fields; especially for medical, antibacterial, and food packaging. This work reports the results for moisture and oxygen transfer of the membranes as a proposed application in food wrapping.

In the automotive industry, there has been considerable focus on developing various sensors for engine oil monitoring. However, when it comes to monitoring the condition of brake fluid, which is crucial for ensuring safety, there has been a lack of a secure online method for this monitoring. This study addresses this gap by developing a hybrid silica nanofiber mat, or an aerogel integrated with an optical fiber sensor, to monitor brake fluid condition. The incorporation of silica nanofibers in this hybrid enhances the sensitivity of the optical fiber glass surface by at least 3.75 times. Furthermore, creating an air gap between the glass surface of the optical fiber and the nanofibers boosts sensitivity by at least 5 times, achieving a better correlation coefficient (R² = 0.98). In the case of silica aerogel, the sensitivity is enhanced by 10 times, but this enhancement relies on the presence of the established air gap. The air gap was adjusted to range from 0.5 mm to 1 mm, without any significant change in the measurement within this range. The response time of the developed sensor is a minimum of 15 min. The sensing material is irreversible and has a diameter of 2.5 mm, making it easily replaceable. Overall, the sensor demonstrates strong repeatability, with approximately 90% consistency, and maintains uncertainty levels below 5% across specific ranges: from 3% to 6% for silica aerogel and from 5% to 6% for silica nanofibers in the presence of an air gap. These findings hold promise for integrating such an optical fiber sensor into a car’s electronic system, enabling the direct online monitoring of brake fluid quality. Additionally, the study elucidates the effect of water absorption on the refractive index of brake fluid, as well as on the silica nanomaterials.

Electrospun nanomaterials and their applications have increasingly gained interest over the last decade. Nanofibers are known for their exceptional surface area and wide opportunities for their functionalization. These properties have been attractive for various sensing applications; however, mostly electric sensing principles have been reported. An overview of most frequently studied concepts will be presented. A novel approach based on optical detection will be described. Various functionalized nanofiber materials have been used to demonstrate feasibility of realization of miniature sensors of biomedical and chemical values (enzymes reactions, metal ions content, concentration, etc.). Compactness and sensitivity of the sensors are significantly enhanced through original hybrid fiber-optic/nanofiber design. The potential of the new detection principle for various applications (bio-medical, chemical, forensic, automotive, etc.) will be discussed.