Ning Tan, Jisun Im, Nigel Neate, Ricky D. Wildman, Georgina Elizabeth Marsh, M. Yee
The evolving bacteria defense mechanism against antimicrobial agents due to the overuse and misuse of antimicrobial chemicals has led to a catastrophic problem - antimicrobial resistance, this has spurred the quest for innovative antibacterial approach to inhibit bacterial growth effectively without using any chemicals. Tailored nano- and microstructured architecture, inspired by natural nanotopography such as those found on cicada wings, hold great promise in antibacterial activity due to their unique mechano-antibacterial properties. Among the various nano-/microfabrication techniques, the two-photon polymerisation (TPP) stands out as a versatile and precise approach to fabricate arbitrarily functional three-dimensional structures with sub-micrometre resolution. The process involves the use of femtosecond laser pulses to induce polymerization of a biocompatible acrylate-based photoresin in a precise spatial pattern to generate the nano-/microarchitecture. In this study, we investigated the influence of key fabrication parameters, such as laser power, exposure time, and interface value to achieve the final pre-defined nano-/microarchitecture. Microscopy analysis showed that nanostructure of heights between 350-650 nm; 300-400 nm diameter; and increasing center-to-center distances of 700-2000 nm were successfully fabricated. The mechano-antibacterial feasibility of the two photon-designed nanoarchitecture were tested against P. aeruginosa pathogenic bacteria commonly encountered in healthcare settings. Our results showed that the TPP nano-/microarchitecture demonstrated intriguing antibacterial activity through physico-mechanical interactions between the nano-/microarchitectures and bacteria, creating surfaces that exhibit bactericidal activity. This study paves the way for advanced antibacterial applications in the field of nanotechnology and biomedicine, making a significant contribution to the ongoing efforts in combating antimicrobial resistance and promoting global health.
{"title":"Revolutionizing Antibacterial Surfaces: 3D Printed Nanoscale and Microscale Topographies through Two-Photon Polymerization","authors":"Ning Tan, Jisun Im, Nigel Neate, Ricky D. Wildman, Georgina Elizabeth Marsh, M. Yee","doi":"10.4028/p-9mqipb","DOIUrl":"https://doi.org/10.4028/p-9mqipb","url":null,"abstract":"The evolving bacteria defense mechanism against antimicrobial agents due to the overuse and misuse of antimicrobial chemicals has led to a catastrophic problem - antimicrobial resistance, this has spurred the quest for innovative antibacterial approach to inhibit bacterial growth effectively without using any chemicals. Tailored nano- and microstructured architecture, inspired by natural nanotopography such as those found on cicada wings, hold great promise in antibacterial activity due to their unique mechano-antibacterial properties. Among the various nano-/microfabrication techniques, the two-photon polymerisation (TPP) stands out as a versatile and precise approach to fabricate arbitrarily functional three-dimensional structures with sub-micrometre resolution. The process involves the use of femtosecond laser pulses to induce polymerization of a biocompatible acrylate-based photoresin in a precise spatial pattern to generate the nano-/microarchitecture. In this study, we investigated the influence of key fabrication parameters, such as laser power, exposure time, and interface value to achieve the final pre-defined nano-/microarchitecture. Microscopy analysis showed that nanostructure of heights between 350-650 nm; 300-400 nm diameter; and increasing center-to-center distances of 700-2000 nm were successfully fabricated. The mechano-antibacterial feasibility of the two photon-designed nanoarchitecture were tested against P. aeruginosa pathogenic bacteria commonly encountered in healthcare settings. Our results showed that the TPP nano-/microarchitecture demonstrated intriguing antibacterial activity through physico-mechanical interactions between the nano-/microarchitectures and bacteria, creating surfaces that exhibit bactericidal activity. This study paves the way for advanced antibacterial applications in the field of nanotechnology and biomedicine, making a significant contribution to the ongoing efforts in combating antimicrobial resistance and promoting global health.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 39","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140212808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Scaffold Carbonated Hydroxyapatite/Honeycomb/Polyethylene Oxide (CHA/HCB/PEO) has been obtained by freeze-drying. The bioceramic CHA used in this study was synthesized from oyster shells using precipitation. HCB and PEO were added as reinforcement materials that affect the crystallographic properties of the scaffold. This study aimed to determine the characteristics of the scaffolds for bone tissue engineering. CHA and scaffolds were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffractometer (XRD), and Scanning Electron Microscopy (SEM). FTIR spectra and XRD graphs confirmed that the CHA produced was B-type. FTIR spectra of the scaffold showed the presence of HCB and PEO in the scaffold, which means they were homogeneously bound in the scaffold solution. XRD test results show that scaffolds' crystallinity and crystallite size tends to decrease compared to CHA. This was good because they could make cells easier to proliferate. A small-scale pore structure (micropore) was also formed in the scaffold. The porosity and pore size of the scaffold were affected by the concentration of CHA. The presence of the micropores can increase the permeability of the scaffold and facilitate cell migration. Thus, the composition of CHA/HCB/PEO scaffolds can be a good candidate material in bone tissue engineering.
碳化羟基磷灰石/蜂窝/聚乙烯氧化物（CHA/HCB/PEO）支架是通过冷冻干燥法获得的。本研究中使用的生物陶瓷 CHA 是利用沉淀法从牡蛎壳中合成的。添加的 HCB 和 PEO 作为增强材料会影响支架的晶体学特性。本研究旨在确定骨组织工程支架的特性。使用傅立叶变换红外光谱仪（FTIR）、X 射线衍射仪（XRD）和扫描电子显微镜（SEM）对 CHA 和支架进行了表征。傅立叶变换红外光谱和 X 射线衍射图证实所生产的 CHA 为 B 型。支架的傅立叶变换红外光谱显示支架中存在六氯苯和聚乙烯醇，这意味着它们在支架溶液中结合均匀。XRD 测试结果表明，与 CHA 相比，支架的结晶度和晶粒尺寸呈下降趋势。这很好，因为它们能使细胞更容易增殖。支架中还形成了小规模的孔隙结构（微孔）。支架的孔隙率和孔径受 CHA 浓度的影响。微孔的存在可增加支架的渗透性，促进细胞迁移。因此，CHA/HCB/PEO 组成的支架可作为骨组织工程中的良好候选材料。
{"title":"Properties of Carbonated Hydroxyapatite-Based Scaffold from Oyster Shells Composited with Honeycomb and Polyethylene Oxide for Bone Tissue Engineering Applications","authors":"Nilam Cahyati, M. Sari, Yusril Yusuf","doi":"10.4028/p-mh0ptj","DOIUrl":"https://doi.org/10.4028/p-mh0ptj","url":null,"abstract":"Scaffold Carbonated Hydroxyapatite/Honeycomb/Polyethylene Oxide (CHA/HCB/PEO) has been obtained by freeze-drying. The bioceramic CHA used in this study was synthesized from oyster shells using precipitation. HCB and PEO were added as reinforcement materials that affect the crystallographic properties of the scaffold. This study aimed to determine the characteristics of the scaffolds for bone tissue engineering. CHA and scaffolds were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffractometer (XRD), and Scanning Electron Microscopy (SEM). FTIR spectra and XRD graphs confirmed that the CHA produced was B-type. FTIR spectra of the scaffold showed the presence of HCB and PEO in the scaffold, which means they were homogeneously bound in the scaffold solution. XRD test results show that scaffolds' crystallinity and crystallite size tends to decrease compared to CHA. This was good because they could make cells easier to proliferate. A small-scale pore structure (micropore) was also formed in the scaffold. The porosity and pore size of the scaffold were affected by the concentration of CHA. The presence of the micropores can increase the permeability of the scaffold and facilitate cell migration. Thus, the composition of CHA/HCB/PEO scaffolds can be a good candidate material in bone tissue engineering.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 31","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140216082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the major objective was to investigate the mechanical and electrical properties, and strain sensibility of the carbon nanotube (CNT) filled epoxidized natural rubber (ENR) nanocomposite. The second filler, cellulose nanofibers (CNFs), at various proportions was incorporated into the CNT-filled ENR nanocomposites. The preparation of ENR nanocomposite was carried out using a latex mixing process. The CNT:CNF hybrid filler was pre-dispersed in deionized water before being added to the ENR latex. The ratios of CNTs to CNFs varied from 1:0 to 1:0.05, 1:0.5, 1:1, 1:1.25, and 1:1.5. Although the presence of CNFs enhanced the stiffness of the substance, its negative effect on the tensile strength was noted. From the evaluated electrical properties, the outcomes demonstrated that the presence of CNFs with suitable proportions can have a positive effect on the performance of the substance when used as a stain-sensitive substance. The electrical conductivity of the hybrid ENR nanocomposite initially increased with the increase of CNF proportion up to 0.5. Beyond this proportion, the conductivity declined gradually. Moreover, the CNT:CNF1:0.5 filled ENR nanocomposite had the highest recoverable piezoresistive property. From this finding, it can be inferred that the CNT:CNF1:0.5 filled ENR nanocomposite is suitable to be used as a strain sensor device.
{"title":"Enhanced Performance of Epoxidized Natural Rubber Nanocomposites for Strain Sensor Application","authors":"Sahatep Trimongkonkool, K. Boonkerd, A. Krainoi","doi":"10.4028/p-9pvoc9","DOIUrl":"https://doi.org/10.4028/p-9pvoc9","url":null,"abstract":"In this study, the major objective was to investigate the mechanical and electrical properties, and strain sensibility of the carbon nanotube (CNT) filled epoxidized natural rubber (ENR) nanocomposite. The second filler, cellulose nanofibers (CNFs), at various proportions was incorporated into the CNT-filled ENR nanocomposites. The preparation of ENR nanocomposite was carried out using a latex mixing process. The CNT:CNF hybrid filler was pre-dispersed in deionized water before being added to the ENR latex. The ratios of CNTs to CNFs varied from 1:0 to 1:0.05, 1:0.5, 1:1, 1:1.25, and 1:1.5. Although the presence of CNFs enhanced the stiffness of the substance, its negative effect on the tensile strength was noted. From the evaluated electrical properties, the outcomes demonstrated that the presence of CNFs with suitable proportions can have a positive effect on the performance of the substance when used as a stain-sensitive substance. The electrical conductivity of the hybrid ENR nanocomposite initially increased with the increase of CNF proportion up to 0.5. Beyond this proportion, the conductivity declined gradually. Moreover, the CNT:CNF1:0.5 filled ENR nanocomposite had the highest recoverable piezoresistive property. From this finding, it can be inferred that the CNT:CNF1:0.5 filled ENR nanocomposite is suitable to be used as a strain sensor device.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140217079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiuling Zhang, J. Kallweit, Mark Pätzel, D. Křemenáková, Jakub Wiener, Kai Yang, Jiri Militky
The textile industry has been weaving polymer optical fibers (POFs) into plane fabric for many years for lighting and decoration. To apply POF-incorporated fabrics in a larger field of application, it is necessary to improve the side illumination of POF-incorporated fabrics. It has been reported that the chemical etching method is one method to enhance the illumination of POFs, while there is little research related to the application of chemical etching to enhance the illumination of POF-incorporated fabrics. In this work, the end emitting POFs (EEPOFs) were used as weft yarns, and polyethylene terephthalate (PET) yarns were used as warp yarns. The POF-incorporated woven PET fabrics were successfully fabricated with a 1/3 twill structure and then treated with a mixture of acetone and methanol (volume ratio: 1:1) for 1 min. The morphology and side illumination of etched POF-incorporated PET fabrics were investigated. As a result, the acetone/methanol mixture destroyed the cladding layer of EEPOFs, and the luminance of etched POF-incorporated PET fabrics was increased by more than 50 %. Besides, acetone/methanol etching resulted in a higher side illumination attenuation behavior.
多年来，纺织业一直将聚合物光纤（POF）编织到平面织物中，用于照明和装饰。要想将加入 POF 的织物应用到更广阔的领域，就必须提高加入 POF 织物的侧面照度。据报道，化学蚀刻法是增强 POF 照亮度的一种方法，而应用化学蚀刻法增强 POF 嵌入织物照明度的相关研究却很少。在这项工作中，采用末端发光 POF（EEPOF）作为纬纱，聚对苯二甲酸乙二醇酯（PET）纱作为经纱。成功制造出具有 1/3 斜纹结构的 POF 嵌入 PET 机织物，然后用丙酮和甲醇（体积比：1:1）混合液处理 1 分钟。研究了蚀刻 POF 嵌入 PET 织物的形态和侧光。结果表明，丙酮/甲醇混合物破坏了 EEPOF 的包层，蚀刻 POF 嵌入 PET 织物的亮度提高了 50%以上。此外，丙酮/甲醇蚀刻还导致了更高的侧光衰减行为。
{"title":"Enhanced Side-Illumination of Etched Polymer Optical Fiber (POF)-Incorporated Woven Polyester (PET) Fabrics","authors":"Xiuling Zhang, J. Kallweit, Mark Pätzel, D. Křemenáková, Jakub Wiener, Kai Yang, Jiri Militky","doi":"10.4028/p-kn4tfj","DOIUrl":"https://doi.org/10.4028/p-kn4tfj","url":null,"abstract":"The textile industry has been weaving polymer optical fibers (POFs) into plane fabric for many years for lighting and decoration. To apply POF-incorporated fabrics in a larger field of application, it is necessary to improve the side illumination of POF-incorporated fabrics. It has been reported that the chemical etching method is one method to enhance the illumination of POFs, while there is little research related to the application of chemical etching to enhance the illumination of POF-incorporated fabrics. In this work, the end emitting POFs (EEPOFs) were used as weft yarns, and polyethylene terephthalate (PET) yarns were used as warp yarns. The POF-incorporated woven PET fabrics were successfully fabricated with a 1/3 twill structure and then treated with a mixture of acetone and methanol (volume ratio: 1:1) for 1 min. The morphology and side illumination of etched POF-incorporated PET fabrics were investigated. As a result, the acetone/methanol mixture destroyed the cladding layer of EEPOFs, and the luminance of etched POF-incorporated PET fabrics was increased by more than 50 %. Besides, acetone/methanol etching resulted in a higher side illumination attenuation behavior.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140220254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Sosiati, Ainur Luthfi Abdul Afif, Azhar Hudiatma, R. K. Adi, Ankas Pamasti
Composites of natural fiber-reinforced thermoplastic and thermoset polymers have been studied for developing prosthetic socket materials. This study investigated the abaca fiber (AF)/carbon fiber (CF)/epoxy (EP) hybrid composite properties: i.e., tensile, flexural, impact, thermal, and water absorption, by varying AF and CF ratios of 1: 0, 0: 1, 2: 1, 3: 1, and 4: 1 with 80 vol% epoxy resin. The cracks formed in bending test specimens were characterized with an optical microscope, whereas the tensile fracture surface was characterized by scanning electron microscopy (SEM). The results confirmed that the mechanical properties of the CF/EP composite are the highest. The higher the AF/CF ratio, the lower the hybrid composite's mechanical properties and the higher the water absorption. The hybrid composite with a 2:1 AF/CF ratio achieved the highest tensile and flexural strengths of 70 MPa and 103 MPa, respectively, and the lowest water absorption of 7.89%. Based on the experimental results, a simulation of the prosthetic socket was performed using Autodesk Inventor 2019 integrated with ANSYS Workbench 2019 R1, resulting in von Mises stress of 2.14 MPa and deformation of 0.015 mm. Besides, its thermal gravimetric analysis (TGA) resulted in good thermal stability.
{"title":"Study of Abaca/Carbon/Epoxy Hybrid Composite Properties as an Alternative Prosthetic Socket Material","authors":"H. Sosiati, Ainur Luthfi Abdul Afif, Azhar Hudiatma, R. K. Adi, Ankas Pamasti","doi":"10.4028/p-8jitl7","DOIUrl":"https://doi.org/10.4028/p-8jitl7","url":null,"abstract":"Composites of natural fiber-reinforced thermoplastic and thermoset polymers have been studied for developing prosthetic socket materials. This study investigated the abaca fiber (AF)/carbon fiber (CF)/epoxy (EP) hybrid composite properties: i.e., tensile, flexural, impact, thermal, and water absorption, by varying AF and CF ratios of 1: 0, 0: 1, 2: 1, 3: 1, and 4: 1 with 80 vol% epoxy resin. The cracks formed in bending test specimens were characterized with an optical microscope, whereas the tensile fracture surface was characterized by scanning electron microscopy (SEM). The results confirmed that the mechanical properties of the CF/EP composite are the highest. The higher the AF/CF ratio, the lower the hybrid composite's mechanical properties and the higher the water absorption. The hybrid composite with a 2:1 AF/CF ratio achieved the highest tensile and flexural strengths of 70 MPa and 103 MPa, respectively, and the lowest water absorption of 7.89%. Based on the experimental results, a simulation of the prosthetic socket was performed using Autodesk Inventor 2019 integrated with ANSYS Workbench 2019 R1, resulting in von Mises stress of 2.14 MPa and deformation of 0.015 mm. Besides, its thermal gravimetric analysis (TGA) resulted in good thermal stability.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140220221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhen Geng, Ye Mao Han, Zheng Rong Zhou, Hao Ying Qi, Yu Chen Zhao, Hao Jian Su, Rong Jin Huang, Lai Feng Li
The determination of the dependencies of the electrical resistivity of the thin film to temperature is of great importance both for understanding the conduction mechanism and for numerous technical applications of these films. In this work, to characterize, the electrical properties of thin films, a GM cryocooler-based automatic board temperature range electrical properties measurement system has been constructed. The system can measure multiple samples simultaneously. The cooling process was simulated using the time-discrete differencing to validate the optimized device design parameters and minimize heat losses. Furthermore, the temperature-dependent sheet resistance results were compared with the results from the physical property measurement system.
{"title":"Design of Electrical Sheet Resistance of Thin Film Measurement System Based on GM Cryocooler in Cryogenic Temperature","authors":"Zhen Geng, Ye Mao Han, Zheng Rong Zhou, Hao Ying Qi, Yu Chen Zhao, Hao Jian Su, Rong Jin Huang, Lai Feng Li","doi":"10.4028/p-ai4edt","DOIUrl":"https://doi.org/10.4028/p-ai4edt","url":null,"abstract":"The determination of the dependencies of the electrical resistivity of the thin film to temperature is of great importance both for understanding the conduction mechanism and for numerous technical applications of these films. In this work, to characterize, the electrical properties of thin films, a GM cryocooler-based automatic board temperature range electrical properties measurement system has been constructed. The system can measure multiple samples simultaneously. The cooling process was simulated using the time-discrete differencing to validate the optimized device design parameters and minimize heat losses. Furthermore, the temperature-dependent sheet resistance results were compared with the results from the physical property measurement system.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140211647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Susanne Fischer, Bahareh Abtahi, Mareen N Warncke, A. Nocke, E. Häntzsche, Chokri Cherif
Motion capture, especially of the knee angle, is an important component for situational triggering of functional electrical stimulation (FES). One major disadvantage of commercial FES devices is their bulky design that prevents unobtrusive wearing in everyday life and limits the patient’s free choice of appearance. This paper presents an alternative approach of sensors for motion capture in form of textile-based strain sensors. These can be integrated in a FES system in form of functional leggings, which make the FES system suitable for an unobtrusive daily use. Textile sensors, especially knitted sensors have already proven to be very promising to detect tensile strain. In particular, weft-knitted strain sensors, which can be integrated directly into the clothing during the knitting process, have the potential to detect the knee angle and therefore derive the gait phase due to the bending of the limbs without disturbing the wearer unnecessarily. Different designs of the weft-knitted strain sensor and their influence on the measurement behaviour of the sensor have been investigated. The weft-knitted strain sensor can be directly integrated in the knee area of the functional leggings to be used as a soft trigger to initiate electrical impulses for FES.
{"title":"Weft-Knitted Strain Sensors for Motion Capture","authors":"Susanne Fischer, Bahareh Abtahi, Mareen N Warncke, A. Nocke, E. Häntzsche, Chokri Cherif","doi":"10.4028/p-b9lrfi","DOIUrl":"https://doi.org/10.4028/p-b9lrfi","url":null,"abstract":"Motion capture, especially of the knee angle, is an important component for situational triggering of functional electrical stimulation (FES). One major disadvantage of commercial FES devices is their bulky design that prevents unobtrusive wearing in everyday life and limits the patient’s free choice of appearance. This paper presents an alternative approach of sensors for motion capture in form of textile-based strain sensors. These can be integrated in a FES system in form of functional leggings, which make the FES system suitable for an unobtrusive daily use. Textile sensors, especially knitted sensors have already proven to be very promising to detect tensile strain. In particular, weft-knitted strain sensors, which can be integrated directly into the clothing during the knitting process, have the potential to detect the knee angle and therefore derive the gait phase due to the bending of the limbs without disturbing the wearer unnecessarily. Different designs of the weft-knitted strain sensor and their influence on the measurement behaviour of the sensor have been investigated. The weft-knitted strain sensor can be directly integrated in the knee area of the functional leggings to be used as a soft trigger to initiate electrical impulses for FES.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140214784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohamad Nasyran Zailan, Khadijah Ismail, Murniati Syaripuddin, Mohd Salman Mohd Sabri
Global warming is a concern nowadays due to excessive release of harmful gasses to the environment, leading to greenhouse effect phenomena worldwide. Based on the data provided by global pollution agencies, the release of greenhouse gasses to the atmosphere is the main cause of pollution and the increase in atmospheric temperature due to warming. Greenhouse gasses (GHGs) contents released to the environment is worrying, with carbon dioxide (CO2) is reported at the highest concentration compared to other gasses. There are many studies conducted to develop and evaluate the performance of harmful gas sensors incorporating inorganic and organic semiconductive materials. Organic semiconductors (OSCs) are environmentally friendly materials, relatively cheaper technology, and comprised of a wide range of materials with good carrier mobility. Therefore, in this work, Organic Thin Film Transistor (OTFT) is developed for gas sensor application. As global warming is becoming more serious, this solution is instead a sustainable solution to the environment, as organic molecules which are held together via Van der Waals bond are easily processed via low-temperature deposition and solution processing as compared to more complicated processes involved in conventional inorganic counterpart. In addition, the developed sensor is generally robust due to the ability to withstand high humidity conditions and can be fabricated on flexible substrates. In this work, suitable materials are identified in basic OTFT construction, which are the electrodes, dielectric and substrate. The scope is mainly focusing on the development of bottom gate OTFT construction, incorporating p-type active material which are Trisisopropylsilylethynyl Pentacene (TIPS Pentacene), Aluminium (Al) as drain and source electrodes, PEDOT: PSS as gate electrode and Polyvinyl alcohol (PVA) as gate dielectric. The materials in bottom gate bottom contact (BGBC) configuration, fabricated via screen printing technique is experimentally tested towards CO2 detection. CO2 is initially detected at 1618 ppm with contact resistance of 15 kΩ, and at 10 ml/minute flow rate, the developed configuration is demonstrated able to achieve sensitivity of 2.069 Ω/ppm. In conclusion, the studied BGBC OTFT has demonstrated suitability and applicability in CO2 gas sensing for sustainable environmental condition monitoring, that could lead to safer environment for the living things on earth. With the proposed dimensions, in the future it is possible to proceed with this work to be fabricated by using more advanced techniques such as photolithography and many others.
{"title":"Experimental Characterisation of BGBC OTFT for Indoor CO2 Gas Sensing","authors":"Mohamad Nasyran Zailan, Khadijah Ismail, Murniati Syaripuddin, Mohd Salman Mohd Sabri","doi":"10.4028/p-rn77vq","DOIUrl":"https://doi.org/10.4028/p-rn77vq","url":null,"abstract":"Global warming is a concern nowadays due to excessive release of harmful gasses to the environment, leading to greenhouse effect phenomena worldwide. Based on the data provided by global pollution agencies, the release of greenhouse gasses to the atmosphere is the main cause of pollution and the increase in atmospheric temperature due to warming. Greenhouse gasses (GHGs) contents released to the environment is worrying, with carbon dioxide (CO2) is reported at the highest concentration compared to other gasses. There are many studies conducted to develop and evaluate the performance of harmful gas sensors incorporating inorganic and organic semiconductive materials. Organic semiconductors (OSCs) are environmentally friendly materials, relatively cheaper technology, and comprised of a wide range of materials with good carrier mobility. Therefore, in this work, Organic Thin Film Transistor (OTFT) is developed for gas sensor application. As global warming is becoming more serious, this solution is instead a sustainable solution to the environment, as organic molecules which are held together via Van der Waals bond are easily processed via low-temperature deposition and solution processing as compared to more complicated processes involved in conventional inorganic counterpart. In addition, the developed sensor is generally robust due to the ability to withstand high humidity conditions and can be fabricated on flexible substrates. In this work, suitable materials are identified in basic OTFT construction, which are the electrodes, dielectric and substrate. The scope is mainly focusing on the development of bottom gate OTFT construction, incorporating p-type active material which are Trisisopropylsilylethynyl Pentacene (TIPS Pentacene), Aluminium (Al) as drain and source electrodes, PEDOT: PSS as gate electrode and Polyvinyl alcohol (PVA) as gate dielectric. The materials in bottom gate bottom contact (BGBC) configuration, fabricated via screen printing technique is experimentally tested towards CO2 detection. CO2 is initially detected at 1618 ppm with contact resistance of 15 kΩ, and at 10 ml/minute flow rate, the developed configuration is demonstrated able to achieve sensitivity of 2.069 Ω/ppm. In conclusion, the studied BGBC OTFT has demonstrated suitability and applicability in CO2 gas sensing for sustainable environmental condition monitoring, that could lead to safer environment for the living things on earth. With the proposed dimensions, in the future it is possible to proceed with this work to be fabricated by using more advanced techniques such as photolithography and many others.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 26","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140216329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jin Bo Liu, Chen Zhang, Xue Hu, Jie Cheng, Zhong Hua Ni, Gu Tian Zhao
Controllable mechanical properties of highly performed Poly (L-lactide acid) (PLLA) monofilaments with oriented molecular structure could widen their applications, especially in biomedical field. Herein, different heat treatments were applied to regulate the degree of molecular relaxation of oriented PLLA monofilaments to tune their mechanical properties. These filaments were manufactured by melting spun and solid-state drawing processes. Then, they were processed by different heat treatments, including annealing, normalizing, and quenching. As the cooling time extension, an obvious molecular orientation loss in filaments happened and increased regularly, and it could reach up to about 35.1% maximumly. However, molecules only in crystal phase were limitedly affected. As a result, mechanical performances of these filaments exhibited a corresponding change after heat treatments. Young’s modulus and elongation at break were promoted after all kinds of post-processes and increased with longer cooling time gradually. But breaking strength showed a contrast change. It means that different heat treatments could be effective avenues to control mechanical properties of oriented PLLA materials by altering the orientation structure.
{"title":"Tailoring Structure-Dominated Mechanical Properties of Poly(L-Lactide Acid) Monofilaments via Controllable Molecular Relaxation","authors":"Jin Bo Liu, Chen Zhang, Xue Hu, Jie Cheng, Zhong Hua Ni, Gu Tian Zhao","doi":"10.4028/p-kuh0lg","DOIUrl":"https://doi.org/10.4028/p-kuh0lg","url":null,"abstract":"Controllable mechanical properties of highly performed Poly (L-lactide acid) (PLLA) monofilaments with oriented molecular structure could widen their applications, especially in biomedical field. Herein, different heat treatments were applied to regulate the degree of molecular relaxation of oriented PLLA monofilaments to tune their mechanical properties. These filaments were manufactured by melting spun and solid-state drawing processes. Then, they were processed by different heat treatments, including annealing, normalizing, and quenching. As the cooling time extension, an obvious molecular orientation loss in filaments happened and increased regularly, and it could reach up to about 35.1% maximumly. However, molecules only in crystal phase were limitedly affected. As a result, mechanical performances of these filaments exhibited a corresponding change after heat treatments. Young’s modulus and elongation at break were promoted after all kinds of post-processes and increased with longer cooling time gradually. But breaking strength showed a contrast change. It means that different heat treatments could be effective avenues to control mechanical properties of oriented PLLA materials by altering the orientation structure.","PeriodicalId":17714,"journal":{"name":"Key Engineering Materials","volume":" 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140217530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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