Minimally invasive interventional surgery techniques using guidewire-based catheters are widely adopted to treat vascular diseases.However,commonly used interventional catheters lack active guidance.The use of guidewi...Minimally invasive interventional surgery techniques using guidewire-based catheters are widely adopted to treat vascular diseases.However,commonly used interventional catheters lack active guidance.The use of guidewires is associated with risks,including increased exposure to X-rays and potential vascular damage during withdrawal from complex vessels.Herein,we developed sub-millimeter microtubular ionic actuators(0.6-0.8 mm outer diameter)integrated into steerable interventional catheters.These actuators can generate large deformations(>10 mm)under 7 V direct current due to enhanced ion migration,enabling precise navigation without the need for guidewires.The designed catheters achieved active bending and accurate positioning in complex arterial vascular branches within a human model.They were also able to navigate within different arterial locations(e.g.,the innominate,subclavian,and carotid arteries)in pigs without the use of guidewires,and even access the ventricle and deliver contrast medium,indicating their great potential for future endovascular therapy.展开更多
Hydraulic electrostatic actuators have become a research hotspot for their inherent flexibility and safety of human-machine interaction.This paper aims to combine the characteristics of dielectric elastomers and fluid...Hydraulic electrostatic actuators have become a research hotspot for their inherent flexibility and safety of human-machine interaction.This paper aims to combine the characteristics of dielectric elastomers and fluid actuators,enhancing the dielectric constant and breakdown field strength by modifying Al_(2)O_(3)on the surface of nanostructured BaTiO3 and in order to develop a hydraulic electrostatic actuator with silicone rubber as the matrix material.Single-factor experiments were firstly conducted to confirm the range of three factors affecting the actuation strain of the actuator:BaTiO_(3)@Al_(2)O_(3)content,thickness of the silicone rubber elastomer film,and pre-stretching ratio coefficient.The response surface methodology was used to study the interactive influence of the above three influencing factors on the actuation strain.It was obtained that A has an insignificant influence on the actuation strain,AB has a significant influence on the actuation strain,and B,C,AC,and BC have a highly influence on the actuation strain.Maximizing actuation strain as the optimization objective yielded the combination results of each factor:BaTiO_(3)@Al_(2)O_(3)content of 2.57%,thickness of 0.60 mm,and pre-stretching ratio coefficient of 2.50.Actuation strain tests were conducted with optimized parameters under no-load.The experimental results of the actuation strain test show that the relative error between the test value and the model prediction value of 16.47%is less than 5%,and the optimization model results are reliable.The optimized hydraulic electrostatic actuator was tested for actuation strain and electrical performance under different loads.The experiment showed that the maximum actuation strain of the hydraulic electrostatic actuator was 17.20%under a load of 100 g.The critical breakdown current of the actuator ranged from 115μA to 130μA,and the maximum electromechanical conversion efficiency of the actuator under different loads was 67.93%.Finally,a joint actuating device was developed based on the structure of the actuator,amplifying the output displacement of the actuator to 30 mm,and the linear displacement of the soft electro-fluid actuator can be converted into a 20°rotation angle through the gear steering mechanism,thus validating the effectiveness of the hydraulic electrostatic actuator.展开更多
基金the National Natural Science Foundation of China(No.52375293)the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and astronautics,Nos.1005-IZD2300225 and IZD2400217)+2 种基金the Nanjing Life and Health Technology Special Project(No.202305031)the Clinical Competence Enhancement Project in Healthcare(No.JSPH-MB-2022-4)the Medical Engineering Translational Fund of Jiangsu Province Hospital(No.NM202402).
文摘Minimally invasive interventional surgery techniques using guidewire-based catheters are widely adopted to treat vascular diseases.However,commonly used interventional catheters lack active guidance.The use of guidewires is associated with risks,including increased exposure to X-rays and potential vascular damage during withdrawal from complex vessels.Herein,we developed sub-millimeter microtubular ionic actuators(0.6-0.8 mm outer diameter)integrated into steerable interventional catheters.These actuators can generate large deformations(>10 mm)under 7 V direct current due to enhanced ion migration,enabling precise navigation without the need for guidewires.The designed catheters achieved active bending and accurate positioning in complex arterial vascular branches within a human model.They were also able to navigate within different arterial locations(e.g.,the innominate,subclavian,and carotid arteries)in pigs without the use of guidewires,and even access the ventricle and deliver contrast medium,indicating their great potential for future endovascular therapy.
基金supported by the National Natural Science Foundation of China[No.52375293]the Open Fund of Laboratory of Aerospace Servo Actuation and Transmission[No.LASAT-2021-05]+1 种基金the Open Fund of Key Laboratory of Advanced Technology for Small and Medium-sized UAVs[No.XCA22054-06]the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and Astronautics)[Nos.1005-ZAG23011,1005-IZD2400217].
文摘Hydraulic electrostatic actuators have become a research hotspot for their inherent flexibility and safety of human-machine interaction.This paper aims to combine the characteristics of dielectric elastomers and fluid actuators,enhancing the dielectric constant and breakdown field strength by modifying Al_(2)O_(3)on the surface of nanostructured BaTiO3 and in order to develop a hydraulic electrostatic actuator with silicone rubber as the matrix material.Single-factor experiments were firstly conducted to confirm the range of three factors affecting the actuation strain of the actuator:BaTiO_(3)@Al_(2)O_(3)content,thickness of the silicone rubber elastomer film,and pre-stretching ratio coefficient.The response surface methodology was used to study the interactive influence of the above three influencing factors on the actuation strain.It was obtained that A has an insignificant influence on the actuation strain,AB has a significant influence on the actuation strain,and B,C,AC,and BC have a highly influence on the actuation strain.Maximizing actuation strain as the optimization objective yielded the combination results of each factor:BaTiO_(3)@Al_(2)O_(3)content of 2.57%,thickness of 0.60 mm,and pre-stretching ratio coefficient of 2.50.Actuation strain tests were conducted with optimized parameters under no-load.The experimental results of the actuation strain test show that the relative error between the test value and the model prediction value of 16.47%is less than 5%,and the optimization model results are reliable.The optimized hydraulic electrostatic actuator was tested for actuation strain and electrical performance under different loads.The experiment showed that the maximum actuation strain of the hydraulic electrostatic actuator was 17.20%under a load of 100 g.The critical breakdown current of the actuator ranged from 115μA to 130μA,and the maximum electromechanical conversion efficiency of the actuator under different loads was 67.93%.Finally,a joint actuating device was developed based on the structure of the actuator,amplifying the output displacement of the actuator to 30 mm,and the linear displacement of the soft electro-fluid actuator can be converted into a 20°rotation angle through the gear steering mechanism,thus validating the effectiveness of the hydraulic electrostatic actuator.
