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In the area of tissue engineering, single screw extrusion (SSE) has gained attention due to its versatility and efficiency in fabricating polymer-based scaffolds. Furthermore, advancements such as the implementation of extrusion techniques and the integration of bioactive agents have significantly expanded the capabilities of SSE. This study aims to investigate the configuration of a custom-designed plastic extrusion for tissue engineering, highlighting its potential in fabricating suture technology for various regenerative biomedical applications. Furthermore, the challenges and future perspectives in SSE technology are discussed, with a focus on the need for additional research to optimize processing parameters, enhance structure bioactivity, and facilitate clinical usage. SSE provides precise regulation of structure morphology, mechanical properties, and porosity, which are critical factors that influence cell behavior and tissue regeneration. Overall, SSE holds great promise as a scalable and cost-effective manufacturing technique for producing polymer-based structures with tailored properties, advancing the field of tissue engineering towards effective clinical solutions. The paper provides a comprehensive overview of a filament extruder production machine that is capable of manufacturing high-quality filament sutures (FS) using thermoplastic materials, specifically bio-protein derived from human serum albumin. The main focus of the paper is to explain the design and operation principles of the filament extruder. The extruder is equipped with a die that can measure a range starting from 2.5 mm and going down to smaller scales. This allows for the extrusion of filaments with a diameter as small as 1.75 mm. Although the design of the extrusion apparatus closely resembles that of commercially available machines, the focus here is on its adaptability and cost-effectiveness for laboratory-scale production. Overall, the research contributes to advancing the understanding of extrusion processing technologies in the context of biomedical applications, with a specific focus on utilizing human serum albumin-derived thermoplastics for manufacturing FS.

AbstractStrain gauges are useful sensors in many engineering and medical applications. When using one gauge for the measurement in quarter-bridge configurations, the elctrical current flowing delivers power to the electrical strain gauge which causes a temperature rise (transient heat effect or THE), with a strain signal appearing as drift of the zero baseline. Fibre optic sensors on the other side are used to measure temperature as well as strain or force. The aim of this study is to evaluate the rise in temperature produced by the electrical strain gauge and to determine the equivalent apparent strain accordingly as a step towards using the reading to correct for the error due to the THE. The results of this study show that the optical fibre sensor is more sensitive compared to the semiconductor sensor used as a reference temperature sensor. The results also show the feasibility of determining the equivalent apparent strain values through reverse calculation of number of fringes resulting from the fibre optic sensor due to the temperature change. This was as an initial step to implement those values in the measuring electronic circuitry in order to eliminate the drift in the zero baselines.

AbstractThe aim of this study is to evaluate the ability of fibre optics in measuring nano-strains developed in dentistry due to small chewing force. Since long fibres were used before, therefore, short fibres were evaluated in this study. In this direction the results from three short fibres sensors (coated with adhesive, coated without adhesive, and uncoated with adhesive) were collected. The results were compared to each other and to strain values from electrical strain gauge. The results revealed superiority of the short fibre with adhesive among all the sensors in sensitivity and accuracy including the strain gauge. The results of the short fibre were, then, compared to results of previous study long fibre. Again, the accuracy of the short fibre sensor was higher than that of the long fibre (deviation of 3% and 12% errors, respectively). In terms of sensitivity, the sensitivity of the short fibre was about 30% of the long fibre. However, sensitivities of both short and long fibres were in the nano-strain region (74 and 17 nano-stains respectively) and were much higher than electrical strain gauge (micro-strain range).

This study aims at comparing the technology of fibre optics to that of electrical strain gauges (ESG) when both are used in the field of dentistry. It compares the accuracy and sensitivity of the strain gauges versus that of optical fibres under the same loading conditions. Results showed that the accuracy of strain gauges is slightly better than that of fibre optics sensor (FOS). However, the errors in the fibre readings showed a pattern that was repeatable in every measurement series and therefore could be corrected through a simple calibration procedure. On the other hand the sensitivity of the FOS was much better than the ESG. Results also showed that using optical sources of lower wavelength improved the sensitivity as well as the accuracy of the optical system.