Introducing static cross-linking points into dynamic covalent polymer gels that display freezing-induced mechanofluorescence: enhanced force transmission efficiency and stability

2019 ◽  
Vol 10 (21) ◽  
pp. 2636-2640 ◽  
Author(s):  
Sota Kato ◽  
Daisuke Aoki ◽  
Hideyuki Otsuka
Keyword(s):  
Mechanical Stress ◽  
Polymer Gels ◽  
Transmission Efficiency ◽  
Cross Linking ◽  
Force Transmission ◽  
Static Cross

Freezing polymer gels that are cross-linked by tetraarylsuccinonitrile (TASN) moieties, which can generate pink and fluorescent yellow radicals in response to mechanical stress, induces mechanofluorescence from the dynamic dissociation of the TASN groups.

Roles of actin cross-linking proteins in the force transmission in stress fiber network

2020 ◽  
Vol 2020.31 (0) ◽  
pp. 1A32
Author(s):  
Gaku MOTOORI ◽  
Tsubasa S. MATSUI ◽  
Daiki MATSUNAGA ◽  
Kentaroh NOI ◽  
Shinji DEGUCHI
Keyword(s):  
Stress Fiber ◽  
Cross Linking ◽  
Force Transmission ◽  
Fiber Network

SU-GG-T-308: Polymer Cross-Linking and Sensitivity Enhancement in Normoxic Polymer Gels Used for Three-Dimensional Dosimetry

2008 ◽  
Vol 35 (6Part14) ◽  
pp. 2796-2796
Author(s):  
R Martin ◽  
J BenComo ◽  
M Heard ◽  
M Martin ◽  
K Kaluarachchi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Polymer Gels ◽  
Sensitivity Enhancement ◽  
Cross Linking

Study on the mechanism and performance of polymer gels by TE and PVA chemical cross‐linking

2021 ◽  
pp. 52043
Author(s):  
Yang Zhou ◽  
Ruizhi Chu ◽  
Lulu Fan ◽  
Xianliang Meng ◽  
Jianqiao Zhao ◽  
...  
Keyword(s):  
Polymer Gels ◽  
Cross Linking ◽  
And Performance ◽  
Chemical Cross Linking

scholarly journals Operation Modes Comparison of a Reconfigurable 3-PRS Parallel Manipulator Based on Kinematic Performance

2016 ◽  
Author(s):  
Siddharth Maraje ◽  
Latifah Nurahmi ◽  
Stéphane Caro
Keyword(s):  
Parallel Manipulator ◽  
Screw Theory ◽  
Operation Mode ◽  
Algebraic Approach ◽  
Transmission Efficiency ◽  
Force Transmission ◽  
Operation Modes ◽  
Transmission Index ◽  
Prismatic Joints ◽  
Kinematic Mapping

The 3-PRS parallel manipulator with different arrangements of prismatic joints is called a reconfigurable 3-PRS parallel manipulator in this paper. The three prismatic joints in PRS limbs are attached to the base with an angle α between the horizontal plane of the base and their directions. Based on [1], the manipulator has identical operation modes, namely x0 = 0 and x3 = 0 for any value of α. Accordingly, this paper presents in more details the performance evaluation of these operation modes by using the output transmission index (OTI) and the constraint transmission index (CTI). The OTI and CTI determine the force transmission efficiency and the constraining ability of the manipulators, respectively. Initially, the determination of the number and types of operation modes of the 3-PRS parallel manipulator is recalled. The computation is carried out by using an algebraic approach, namely the Study kinematic mapping. In each operation mode, the actuation wrenches and the constraint wrenches are obtained based on the Screw theory. Then, the OTI and CTI are traced in the orientation workspace of the manipulator for different values of angle α. Furthermore, the singularity conditions are analysed corresponding to the values of OTI and CTI.

scholarly journals Mechanism design and parameter optimization of a new asymmetric translational parallel manipulator

2019 ◽  
Vol 10 (1) ◽  
pp. 255-272
Author(s):  
Yi Yang ◽  
Yaqi Tang ◽  
Haijun Chen ◽  
Yan Peng ◽  
Huayan Pu
Keyword(s):  
Mechanism Design ◽  
Parallel Manipulator ◽  
Transmission Efficiency ◽  
Condition Numbers ◽  
Design Parameters ◽  
Evaluation Function ◽  
Force Transmission ◽  
Heavy Load ◽  
Pick And Place ◽  
Pick And Place Operation

Abstract. With the requirement of heavy load for pick-and-place operation, a new 3-DoF asymmetric translational parallel manipulator is invented in this paper. This manipulator is assembled by a kinematic limb with the parallel linear motion elements(PLMEs), and a single loop 2-UPR. Owning to the linear actuators directly connecting the moving and the fixed platforms, this parallel manipulator has high force transmission efficiency, and adapts to pick-and-place operation under heavy load. In this paper, the mobility and singularity are firstly analyzed by screw theory. And the simplified kinematic and dynamic model is established and solved. Secondly, the reaction forces of the prismatic joints in the PLMEs limb are investigated for the mechanism design. Also, the overall performance of the whole manipulator, such as the workspace, condition numbers of Jacobian matrices and motion transmission, etc, are discussed. Thirdly, a compound evaluation function, which involves the factors of workspace volume, transmission efficiency and reaction force, is proposed. In order to obtain a set of better design parameters, the optimization of the 3-DoF translational manipulator is conducted, for the object of maximum of the evaluation function. At last, the prototype is manufactured and experimented to validate the mobility and motion feasibility of this mechanism design.

Preparation and evaluation of PAMAM dendrimer-based polymer gels physically cross-linked by hydrogen bonding

2019 ◽  
Vol 7 (9) ◽  
pp. 3918-3925 ◽  
Author(s):  
Hailin Cong ◽  
Liping Zhou ◽  
Qingye Meng ◽  
Yixin Zhang ◽  
Bing Yu ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Antibacterial Properties ◽  
Polymer Gels ◽  
Pamam Dendrimer ◽  
Covalent Bonding ◽  
Cross Linking ◽  
Anti Inflammatory ◽  
Preparation And Evaluation

Dendrimer-based polymer gels with good antibacterial properties and anti-inflammatory properties were prepared without any covalent bonding cross-linking agents.

scholarly journals Spatio-temporal mapping of mechanical force generated by macrophages during FcγR-dependent phagocytosis reveals adaptation to target stiffness

2020 ◽  
Author(s):  
Pablo Rougerie ◽  
Dianne Cox
Keyword(s):  
Mechanical Stress ◽  
Mechanical Response ◽  
Temporal Dynamics ◽  
Traction Force ◽  
Substrate Stiffness ◽  
Force Transmission ◽  
Atypical Form ◽  
Macrophage Phagocytosis ◽  
Spatio Temporal ◽  
Frustrated Phagocytosis

ABSTRACTMacrophage phagocytosis is a strikingly flexible process central to pathogen clearance and is an attractive target for the development of anti-cancer immunotherapies. To harness the adaptability of phagocytosis, we must understand how macrophages can successfully deform their plasma membrane. While the signaling pathways and the molecular motors responsible for this deformation have been studied for many years, we only have limited insight into the mechanics that drive the formation of the phagocytic cup. Using Traction Force Microscopy (TFM), we have been able to characterize the spatio-temporal dynamics of mechanical forces generated in the course of FcγR-dependent frustrated phagocytosis and we determined whether this was affected by the stiffness of the potential phagocytic targets. We observed that frustrated phagocytosis is an atypical form of spreading where the cell deformation rate is unaffected by the substrate stiffness. Interestingly, the cell initially extends without forces being recorded then switches to a mode of pseudopod extension involving spatially organized force transmission. Importantly we demonstrate that macrophages adapt to the substrate stiffness primarily through a modulation of the magnitude of mechanical stress exerted, and not through modification of the mechanical stress kinetics or distribution. Altogether, we suggest that macrophage phagocytosis exhibits a clear resilience to variations of the phagocytic target stiffness and this is favored by an adaptation of their mechanical response.

Swelling and mechanical properties of polymer gels with cross-linking gradient

Soft Matter ◽  
2010 ◽  
Vol 6 (15) ◽  
pp. 3455 ◽  
Author(s):  
Paulo A. L. Fernandes ◽  
Stephan Schmidt ◽  
Michael Zeiser ◽  
Andreas Fery ◽  
Thomas Hellweg
Keyword(s):  
Mechanical Properties ◽  
Polymer Gels ◽  
Cross Linking

Evaluation of transradial body-powered prostheses using a robotic simulator

2016 ◽  
Vol 41 (2) ◽  
pp. 194-200 ◽  
Author(s):  
Rafi Ayub ◽  
Dario Villarreal ◽  
Robert D Gregg ◽  
Fan Gao
Keyword(s):  
Grip Force ◽  
Transmission Efficiency ◽  
Optimal Operation ◽  
Body Posture ◽  
Force Transmission ◽  
Skin Breakdown ◽  
Shoulder Flexion ◽  
Human Arm ◽  
Sound Side ◽  
Robotic Simulator

Background: Transradial body-powered prostheses are extensively used by upper-limb amputees. This prosthesis requires large muscle forces and great concentration by the patient, often leading to discomfort, muscle fatigue, and skin breakdown, limiting the capacity of the amputee to conduct daily activities. Since body-powered prostheses are commonplace, understanding their optimal operation to mitigate these drawbacks would be clinically meaningful. Objectives: To find the optimal operation of the prosthesis where the activation force is minimized and the grip force is maximized. Study design: Experimental design. Methods: A computer-controlled robotic amputee simulator capable of rapidly testing multiple elbow, shoulder, and scapular combinations of the residual human arm was constructed. It was fitted with a transradial prosthesis and used to systematically test multiple configurations. Results: We found that increased shoulder flexion, scapular abduction, elbow extension, and the placement of the ring harness near the vertebra C7 correlate with higher gripper operation efficiency, defined as the ratio of grip force to cable tension. Conclusion: We conclude that force transmission efficiency is closely related to body posture configuration. These results could help guide practitioners in clinical practice as well as motivate future studies in optimizing the operation of a body-powered prosthesis. Clinical relevance The results from this study suggest that clinicians ought to place the ring harness inferior and to the sound side of the vertebra prominens in order to maximize grip efficiency. The results will also help clinicians better instruct patients in body posture during prosthesis operation to minimize strain.

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