In order to imitate skin characteristics, a dielectric elastomer (DE) membrane coated with flexible electrodes is applied with high voltage, which can lead to wrinkles and other phenomena. To develop soft-actuated air...In order to imitate skin characteristics, a dielectric elastomer (DE) membrane coated with flexible electrodes is applied with high voltage, which can lead to wrinkles and other phenomena. To develop soft-actuated air vehicles and other equipment, lightweight gas is pumped into a DE spherical shell to generate controllable flight movements. According to experimental phenomena and data, the calculation models of phase transitions on circular DE films are built. Meanwhile, the deformation characteristics of different DE (acrylic polymer and rubber) spherical actuators combined with helium are compared. The peak pressure inside a rubber balloon is greater than that of a VHB (acrylic polymer) balloon shell, but the limit stretch of rubber is much smaller. By taking advantages of this phenomenon, large deformations of a VHB spherical shell can be realized at an actuated state. Moreover, multi-layer spherical DE shells can achieve larger voltage-induced volume change than monolayer ones. The research indicates that pre-stretching is one of the key factors to induce phase transitions between flat, wrinkled and bulging regions on circular DE films, and the internal pressure determines the electromechanical performance of balloon actuators.展开更多
Although dielectric elastomer(DE)with substantial actuated strain(AS)has been reported 20 years ago,its scientific understanding remains unclear.The most accepted theory of DE,which is proposed in 2000,holds the view ...Although dielectric elastomer(DE)with substantial actuated strain(AS)has been reported 20 years ago,its scientific understanding remains unclear.The most accepted theory of DE,which is proposed in 2000,holds the view that AS of DE is induced by the Maxwell stress.According to this theory,materials have similar ratios of permittivity and Young’s modulus should have similar AS,while the experimental results are on contrary to this theory,and the experimental AS has no relationship with ideal AS.Here,a new dipole-conformation-actuated strain cross-scale model is proposed,which can be generally applied to explain the AS of DE without pre-strain.According to this model,several characteristics of an ideal DE are listed in this work and a new DE based on polyphosphazene(PPZ)is synthesized.The AS of PPZ can reach 84%without any pre-strain.At last,a PPZ-based all soft artificial heart(ASAH)is built,which works in the similar way with natural myocardium,indicating that this material has great application potential and possibility in the construction of an ASAH for heart failure(HF)patients.展开更多
基金The National Natural Science Foundation of China(No.51775108)
文摘In order to imitate skin characteristics, a dielectric elastomer (DE) membrane coated with flexible electrodes is applied with high voltage, which can lead to wrinkles and other phenomena. To develop soft-actuated air vehicles and other equipment, lightweight gas is pumped into a DE spherical shell to generate controllable flight movements. According to experimental phenomena and data, the calculation models of phase transitions on circular DE films are built. Meanwhile, the deformation characteristics of different DE (acrylic polymer and rubber) spherical actuators combined with helium are compared. The peak pressure inside a rubber balloon is greater than that of a VHB (acrylic polymer) balloon shell, but the limit stretch of rubber is much smaller. By taking advantages of this phenomenon, large deformations of a VHB spherical shell can be realized at an actuated state. Moreover, multi-layer spherical DE shells can achieve larger voltage-induced volume change than monolayer ones. The research indicates that pre-stretching is one of the key factors to induce phase transitions between flat, wrinkled and bulging regions on circular DE films, and the internal pressure determines the electromechanical performance of balloon actuators.
基金supported by the Basic Science Center Program of the National Natural Science Foundation of China (51988102)the National Key Research and Development Program of China (2017YFB0306903)+2 种基金the Major Program of National Natural Science Foundation of China (51790501)the Innovative Research Groups (51221002 and 51521062)the National Natural Science Foundation of China (52003024)
文摘Although dielectric elastomer(DE)with substantial actuated strain(AS)has been reported 20 years ago,its scientific understanding remains unclear.The most accepted theory of DE,which is proposed in 2000,holds the view that AS of DE is induced by the Maxwell stress.According to this theory,materials have similar ratios of permittivity and Young’s modulus should have similar AS,while the experimental results are on contrary to this theory,and the experimental AS has no relationship with ideal AS.Here,a new dipole-conformation-actuated strain cross-scale model is proposed,which can be generally applied to explain the AS of DE without pre-strain.According to this model,several characteristics of an ideal DE are listed in this work and a new DE based on polyphosphazene(PPZ)is synthesized.The AS of PPZ can reach 84%without any pre-strain.At last,a PPZ-based all soft artificial heart(ASAH)is built,which works in the similar way with natural myocardium,indicating that this material has great application potential and possibility in the construction of an ASAH for heart failure(HF)patients.
