To achieve high durability and excellent mechanical performances of cementitious materials, research on fiber-reinforced cementitious composites (FRCC) containing various fibers has been actively conducted. On the other hand, in robotics and other fields, research on artificial muscles using Twisted and Coiled Polymer Actuator (TCPA), which have similar functions to human muscle fibers, has attracted much attention. In this study, use of this TCPA as a reinforcing fiber in high performance FRCC (HPFRCC) was proposed. The employed TCPA has a structure of coiled nylon fibers with wrapping stainless-steel fibers. The effect of the TCPA and its shrinkage motion on the crack dispersion properties of HPFRCC was investigated. The experimental results showed that the strain-hardening with multiple cracks in HPFRCC continued up to more than 7% of the ultimate strain when the TCPA was electrically stimulated to shrinkage motion. This information indicates that the TCPA has high potential to further improve HPFRCC performance.
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http://dx.doi.org/10.3390/ma15165701 | DOI Listing |
Materials (Basel)
December 2024
Institute of Metrology and Biomedical Engineering, Warsaw University of Technology, A. Boboli 8, 02-525 Warsaw, Poland.
The magnetoelastic effect is known as the dependence between the magnetic properties of the material and applied mechanical stress. The stress might not be applied directly but rather generated by the applied torque. This creates the possibility of developing a torque-sensing device based on the magnetoelastic effect.
View Article and Find Full Text PDFJ Robot Surg
December 2024
National Engineering Research Center of Neuromodulation, School of Aerospace Engineering, Tsinghua University, Beijing, 100084, China.
Magnetic resonance imaging (MRI) offers high-quality soft tissue imaging without radiation exposure, which allows stereotactic techniques to significantly improve outcomes in cranial surgeries, particularly in deep brain stimulation (DBS) procedures. However, conventional stereotactic neurosurgeries often rely on mechanical stereotactic head frames and preoperative imaging, leading to suboptimal results due to the invisibility and the contact with patient's head, which may cause additional harm. This paper presents a frameless, MRI-guided stereotactic neurosurgical robotic system.
View Article and Find Full Text PDFHua Xi Kou Qiang Yi Xue Za Zhi
December 2024
Institute of Stomatology, Binzhou Medical University, Yantai 264000, China.
Objectives: This study aimed to investigate the effects of silencing Ras homolog family member C (RhoC) on the proliferation, apoptosis, invasion, migration, and epithelial-mesenchymal transition (EMT) of salivary adenoid cystic carcinoma (SACC) and its molecular mechanisms.
Methods: A total of 27 SACC lesions and normal salivary gland tissues that were surgically resected at Qingdao Municipal Hospital from January 1, 2019 to March 1, 2024 were selected, and the expression levels of RhoC were detected by Western blot and immunohistochemistry. Three small interfering RNA (siRNAs) were designed to target the RhoC gene sequence, transfected into SACC-LM and SACC-83 cell lines, and evaluated for transfection efficiency.
Small
October 2024
Advanced Materials Division, Korea Research Institute of Chemical Technology, Daejeon, 34114, Republic of Korea.
As actuated devices become smaller and more complex, there is a need for smart materials and structures that directly function as complete mechanical units without an external power supply. The strategy uses light-powered, twisted, and coiled azobenzene-functionalized semicrystalline liquid crystal elastomer (AC-LCE) springs. This twisting and coiling, which has previously been used for only thermally, electrochemically, or absorption-powered muscles, maximizes uniaxial and radial actuation.
View Article and Find Full Text PDFPolymers (Basel)
September 2024
College of Textile Science and Engineering (International Institute of Silk), Zhejiang Sci-Tech University, Hangzhou 310018, China.
Electro-conductive films with excellent flexibility and thermal behavior have great potential in the fields of wearable electronics, artificial muscle, and soft robotics. Herein, we report a super-elastic and electro-conductive composite film with a sandwich structure. The composite film was constructed by spraying Polyvinyl alcohol (PVA) polymers onto a buckled conductive carbon nanotube-polydimethylsiloxane (CNTs-PDMS) composite film.
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