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ACS Nano Jun 2024Smart textiles capable of both energy harvesting and multifunctional sensing are highly desirable for next-generation portable electronics. However, there are still...
Smart textiles capable of both energy harvesting and multifunctional sensing are highly desirable for next-generation portable electronics. However, there are still challenges that need to be conquered, such as the innovation of an energy-harvesting model and the optimization of interface bonding between fibers and active materials. Herein, inspired by the spiral structure of natural vines, a highly stretchable triboelectric helical yarn (TEHY) was manufactured by twisting the carbon nanotube/polyurethane nanofiber (CNT/PU NF) Janus membrane. The TEHY had a zebra-stripe-like design that was composed of black interval conductive CNTs and white insulative PU NFs. Due to the different electron affinity, the zebra-patterned TEHY realized a self-frictional triboelectric effect because the numerous microscopic CNT/PU triboelectric interfaces generated an alternating current in the external conductive circuit without extra external friction layers. The helical geometry combined with the elastic PU matrix endowed TEHY with superelastic stretchability and outstanding output stability after 1000 cycles of the stretch-release test. By virtue of the robust mechanical and electrical stability, the TEHY can not only be used as a high-entropy mechanical energy harvester but also serve as a self-powered sensor to monitor the stretching or deforming stimuli and human physiological activities in real time. These merits manifested the versatile applications of TEHY in smart fabrics, wearable power supplies, and human-machine interactions.
PubMed: 38907712
DOI: 10.1021/acsnano.4c03115 -
Medical Engineering & Physics Jul 2024Anchorage, evaluated by the maximum insertion torque (IT), refers to mechanical engagement between dental implant and host bone at the time of insertion without external...
Anchorage, evaluated by the maximum insertion torque (IT), refers to mechanical engagement between dental implant and host bone at the time of insertion without external loads. Sufficient anchorage has been highly recommended in the clinic. In several studies, the effects of implant diameter and taper body design under external loading have been evaluated after insertion; however, there are few studies, in which their effects on stress distribution during insertion have been investigated to understand establishment of anchorage. Therefore, the objective of this study was to investigate the effects of dental implant diameter and tapered body design on anchorage combining experiments, analytical modeling, and finite element analysis (FEA). Two implant designs (parallel-walled and tapered) with two implant diameters were inserted into rigid polyurethane (PU) foam with corresponding straight drill protocols. The IT was fit to the analytical model (R = 0.88-1.0). The insertion process was modeled using explicit FEA. For parallel-walled implants, normalized IT and final FEA contact ratio were not related to the implant diameter while the implant diameter affected normalized IT (R = 0.90, p < 0.05, β = 0.20 and β = 0.93, standardized regression coefficients for implant diameter and taper body design) and final FEA contact ratio of tapered implants. The taper design distributed the PU foam stress further away from the thread compared to parallel-walled implants, which demonstrated compression in PU foam established by the tapered body during insertion.
Topics: Polyurethanes; Dental Implants; Finite Element Analysis; Stress, Mechanical; Torque; Materials Testing
PubMed: 38906568
DOI: 10.1016/j.medengphy.2024.104181 -
International Journal of Biological... Jun 2024In order to fulfill the demands for degradability, a broad working range, and heightened sensitivity in flexible sensors, biodegradable polyurethane (BTPU) was...
Biodegradable poly(lactic acid) blocked polyurethane/carbon nanotubes coated cotton fabric prepared by ultrasonic-assisted inkjet printing for high performance strain sensors.
In order to fulfill the demands for degradability, a broad working range, and heightened sensitivity in flexible sensors, biodegradable polyurethane (BTPU) was synthesized and combined with CNTs to produce BTPU/CNTs coated cotton fabric using an ultrasonic-assisted inkjet printing process. The synthesized BTPU displayed a capacity for degradation in a phosphate buffered saline solution, resulting in a weight loss of 25 % after 12 weeks of degradation. The BTPU/CNTs coated cotton fabric sensor achieved an extensive strain sensing range of 0-137.5 %, characterized by high linearity and a notable sensitivity (gauge factor (GF) of 126.8). Notably, it demonstrated a low strain detection limit (1 %), rapid response (within 280 ms), and robust durability, enabling precise monitoring of both large and subtle human body movements such as finger, wrist, neck, and knee bending, as well as swallowing. Moreover, the BTPU/CNTs coated cotton fabric exhibited favorable biocompatibility with human epidermis, enabling potential applications as wearable skin-contact sensors. This work provides insight into the development of degradable and high sensing performance sensors suitable for applications in electronic skins and health monitoring devices.
PubMed: 38906353
DOI: 10.1016/j.ijbiomac.2024.133269 -
Biomedical Physics & Engineering Express Jun 2024In this study tissue equivalency of the polymeric materials was investigated by comparing with ICRP 110 Male Adult Computational Phantom tissues. For this purpose,...
In this study tissue equivalency of the polymeric materials was investigated by comparing with ICRP 110 Male Adult Computational Phantom tissues. For this purpose, radiological properties of polyamide (PA), high density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMWPE), polypropylene (PP), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), polyoxymethylene (POM) and polyurethane foam (PU FOAM) were evaluated in the diagnostic energy range (15-150 keV). The radiological properties of the materials and ICRP 110 Male and Female Adult Computational Phantom tissues were calculated with Phy-X/PSD software. No major differences were seen except for sex-specific organs, and comparisons were made using an adult male phantom. To confirm the results experimentally, a chest phantom was designed with the polymeric materials. The phantom was scanned by Siemens SOMATOM Edge CT device with tube voltage of 120 kVp and Hounsfield Unit (HU) values were measured. In addition, HU values were calculated using theoretical relationships and significant agreement was obtained between measured and calculated HUs. It was determined that PA, PP, UHMWPE and HDPE were equivalent to muscle and adipose tissue, PVC and PTFE were equivalent to mineral bone, PET and POM were equivalent to spongiosa bone and PU FOAM was equivalent to lung tissue. .
PubMed: 38906123
DOI: 10.1088/2057-1976/ad5a9d -
Biomaterials Jun 2024Biohybrid tissue-engineered vascular grafts (TEVGs) promise long-term durability due to their ability to adapt to hosts' needs. However, the latter calls for sensitive...
Biohybrid tissue-engineered vascular grafts (TEVGs) promise long-term durability due to their ability to adapt to hosts' needs. However, the latter calls for sensitive non-invasive imaging approaches to longitudinally monitor their functionality, integrity, and positioning. Here, we present an imaging approach comprising the labeling of non-degradable and degradable TEVGs' components for their in vitro and in vivo monitoring by hybrid H/F MRI. TEVGs (inner diameter 1.5 mm) consisted of biodegradable poly(lactic-co-glycolic acid) (PLGA) fibers passively incorporating superparamagnetic iron oxide nanoparticles (SPIONs), non-degradable polyvinylidene fluoride scaffolds labeled with highly fluorinated thermoplastic polyurethane (F-TPU) fibers, a smooth muscle cells containing fibrin blend, and endothelial cells. H/F MRI of TEVGs in bioreactors, and after subcutaneous and infrarenal implantation in rats, revealed that PLGA degradation could be faithfully monitored by the decreasing SPIONs signal. The F signal of F-TPU remained constant over weeks. PLGA degradation was compensated by cells' collagen and α-smooth-muscle-actin deposition. Interestingly, only TEVGs implanted on the abdominal aorta contained elastin. XTT and histology proved that our imaging markers did not influence extracellular matrix deposition and host immune reaction. This concept of non-invasive longitudinal assessment of cardiovascular implants using H/F MRI might be applicable to various biohybrid tissue-engineered implants, facilitating their clinical translation.
PubMed: 38906013
DOI: 10.1016/j.biomaterials.2024.122669 -
Marine Genomics Jun 2024Environmental DNA (eDNA) analyses of species present in marine environments is the most effective biological diversity measurement tool currently available. eDNA...
Environmental DNA (eDNA) analyses of species present in marine environments is the most effective biological diversity measurement tool currently available. eDNA sampling methods are an intrinsically important part of the eDNA biodiversity analysis process. Identification and development of eDNA sampling methods that are as rapid, affordable, versatile and practical as possible will improve rates of detection of marine species. Optimal outcomes of eDNA biodiversity surveys come from studies employing high levels of sampling replication, so any methods that make sampling faster and cheaper will improve scientific outcomes. eDNA sampling methods that can be applied more widely will also enable sampling from a greater range of marine surface micro-habitats, resulting in detection of a wider range of organisms. In this study, we compared diversity detection by several methods for sampling eDNA from submerged marine surfaces: polyurethane foam, nylon swabs, microfibre paint rollers, and sediment scoops. All of the methods produced a diverse range of species identifications, with >250 multicellular species represented by eDNA at the study site. We found that widely-available small paint rollers were an effective, readily available and affordable method for sampling eDNA from underwater marine surfaces. This approach enables the sampling of marine eDNA using extended poles, or potentially by remotely operated vehicles, where surface sampling by hand is impractical.
PubMed: 38905943
DOI: 10.1016/j.margen.2024.101127 -
Journal of Materials Chemistry. B Jun 2024Coating metal structures with a protective material is a popular strategy to prevent their deterioration due to corrosion. However, maintaining the barrier properties of...
Coating metal structures with a protective material is a popular strategy to prevent their deterioration due to corrosion. However, maintaining the barrier properties of coatings after their mechanical damage is challenging. Herein, we prepared multifunctional coatings with self-healing ability to conserve their anticorrosion performance after damage. The coating was formed by blending synthesized redox-responsive copolymers with the ability to release a corrosion inhibitor upon the onset of corrosion with synthesized self-healing polyurethanes containing disulfide bonds. The corrosion rate of steel substrates coated with a blend is approximately 24 times lower than that of steel coated with only self-healing polyurethane. An exceptional healing efficiency, as high as 95%, is obtained after mechanical damage. The antibiofouling property against bacterial and microalgal attachments on coatings is facilitated by the repellent characteristic of fluorinated segments and the biocidal activity of the inhibitor moieties in the copolymer.
PubMed: 38904191
DOI: 10.1039/d4tb00736k -
Journal of Otolaryngology - Head & Neck... 2024Minimally invasive cochlear implant surgery by using a microstereotactic frame demands solid connection to the bone. We aimed to determine the stability of commercially...
BACKGROUND
Minimally invasive cochlear implant surgery by using a microstereotactic frame demands solid connection to the bone. We aimed to determine the stability of commercially available orthodontic miniscrews to evaluate their feasibility for frame's fixation. In addition, which substitute material most closely resembles the mechanical properties of the human temporal bone was evaluated.
METHODS
Pull-out tests were carried out with five different types of orthodontic miniscrews in human temporal bone specimens. Furthermore, short fiber filled epoxy (SFFE), solid rigid polyurethane (SRPU50), bovine femur, and porcine iliac bone were evaluated as substitute materials. In total, 57 tests in human specimens and 180 tests in the substitute materials were performed.
RESULTS
In human temporal bone, average pull-out forces ranged from 220 N to 285 N between screws. Joint stiffness in human temporal bone ranged between 14 N/mm and 358 N/mm. Statistically significant differences between the tested screws were measured in terms of stiffness and elastic energy. One screw type failed insertion due to tip breakage. No significant differences occurred between screws in maximum pull-out force. The average pull-out values of SFFE were 14.1 N higher compared to human specimen.
CONCLUSION
Orthodontic miniscrews provided rigid fixation when partially inserted in human temporal bone, as evidenced by pull-out forces and joint stiffness. Average values exceeded requirements despite variations between screws. Differences in stiffness and elastic energy indicate screw-specific interface mechanics. With proper insertion, orthodontic miniscrews appear suitable for microstereotactic frame anchoring during minimally invasive cochlear implant surgery. However, testing under more complex loading is needed to better predict clinical performance. For further pull-out tests, the most suitable substitute material is SFFE.
Topics: Temporal Bone; Humans; Bone Screws; Animals; Swine; Cochlear Implantation; Materials Testing; Cadaver; Cattle; Minimally Invasive Surgical Procedures
PubMed: 38903014
DOI: 10.1177/19160216241248669 -
Scientific Reports Jun 2024Absorption methods using polyurethane foams (PUFs) have recently gained popularity in treating oil spills. However, conventional petroleum-based PUFs lack selectivity...
Absorption methods using polyurethane foams (PUFs) have recently gained popularity in treating oil spills. However, conventional petroleum-based PUFs lack selectivity and are commonly surface-modified using complicated processes that require toxic and harmful solvents to enhance their hydrophobicity and oil sorption capacities. In this paper, a novel naturally superoleophilic foam with inherent hydrophobic properties has been developed through the conventional one-shot foaming method with the integration of coconut oil-based polyol. This bio-based polyol was explicitly handpicked as it is chiefly saturated, highly abundant, and inexpensive. The foam is characterized by an oil sorption capacity range of 14.89-24.65 g g for different types of oil, equivalent to 578-871 times its weight. Its hydrophobic behavior is expressed through a water contact angle of ~ 139°. The foam also showcased excellent chemical stability and high recyclability without a significant loss in absorption capacity after 20 cycles. The incorporation of the coconut oil-based polyol is also shown to improve the morphological, mechanical, and thermal behavior of the foam. It can be inferred from these findings that this novel material holds great potential for revolutionizing sorbents, pioneering a more sustainable and eco-friendly functional material produced via a facile method.
PubMed: 38902271
DOI: 10.1038/s41598-024-64178-2 -
Biomedical Materials (Bristol, England) Jun 2024Nowadays, medical polyurethanes with favorable and durable antibacterial properties received more attention, because of avoiding repeated replacement of interventional...
Nowadays, medical polyurethanes with favorable and durable antibacterial properties received more attention, because of avoiding repeated replacement of interventional materials and reducing patients' pain. In this thesis, non-soluble antibacterial polyurethane (NAPU) based on cation antibacterial mechanism was prepared by photo-grafting chitosan azide and heparin azide into polyurethane (PU). -NHof chitosan azide absorbed bacteria, inhibiting and breaking their mobility and structures. Heparin azide prevented cations from penetrating bacteria's membranes and inhibited their growth. The results showed that chitosan azide and heparin azide were successfully grafted into PU. The highest antibacterial rate was 92.07%, cytotoxicity grade ranging from 0-1 (RGR standard) and water contact angle exhibiting 60°, attributing to cation antibacterial effect and -OH existing. Tensile strength was up to 23.91 MPa and was suitable for using as medical materials. NAPU with long-lasting coating both possessed antibacterial properties and persistence, which can solve the problem of medical catheters' long-term using.
Topics: Polyurethanes; Chitosan; Anti-Bacterial Agents; Heparin; Azides; Cations; Materials Testing; Tensile Strength; Escherichia coli; Biocompatible Materials; Animals; Humans; Microbial Sensitivity Tests; Staphylococcus aureus; Mice; Solubility
PubMed: 38901421
DOI: 10.1088/1748-605X/ad5a5c