Rotational energy is a type of common energy source that can be harvested for supplying low-powered electronic devices.This paper proposes and investigates a novel cam-like dielectric elastomer generator(CDEG)for high...Rotational energy is a type of common energy source that can be harvested for supplying low-powered electronic devices.This paper proposes and investigates a novel cam-like dielectric elastomer generator(CDEG)for high-performance rotational energy harvesting.A mushroom-head clamp is designed to form a type of advanced conical dielectric elastomer membranes(DEMs).Moreover,a type of multi-protrusion cam mechanism is designed in the CDEG to effectively convert any external rotational excitation into a linear reciprocating motion,which can be further converted into electricity through the DEMs.First,the operating principle of the system under external rotational excitation is analyzed theoretically by deducing the deformation condition of the DEMs and the electrical output of the system.Second,the prototype is fabricated,and the rotational-to-linear motion conversion rule of its cam-like mechanism and the DEM capacitance calculation approach are validated.The experimental results show that adequate charging time and discharging time of the DEMs,which can be realized through the proposed cam-like mechanisms,are beneficial to the energy harvesting(EH)performance of the system.Third,with the validated theoretical model,numerical simulations are conducted to further study the system dynamics and the influences of important system parameters on the EH performance to provide a guideline for system improvement.Finally,the genetic algorithm is adopted to obtain the optimal system parameters and the corresponding electrical output of the proposed CDEG,demonstrating its superior output power at ultralow rotational frequencies compared with other typical rotational energy harvesters in the literature.展开更多
In this paper,we propose an ultrabroadband chiral metasurface(CMS)composed of S-shaped resonator structures situated between two twisted subwavelength gratings and dielectric substrate.This innovative structure enable...In this paper,we propose an ultrabroadband chiral metasurface(CMS)composed of S-shaped resonator structures situated between two twisted subwavelength gratings and dielectric substrate.This innovative structure enables ultrabroadband and high-efficiency linear polarization(LP)conversion,as well as asymmetric transmission(AT)effect in the microwave region.The enhanced interference effect of the Fabry-Perot-like resonance cavity greatly expands the bandwidth and efficiency of LP conversion and AT effect.Through numerical simulations,it has been revealed that the cross-polarization transmission coefficients for normal forward(-z)and backward(+z)incidence exceed 0.8 in the frequency range of 4.13 to 17.34 GHz,accompanied by a polarization conversion ratio of over 99%.Furthermore,our microwave experimental results validate the consistency among simulation,theory,and measurement.Additionally,we elucidate the distinct characteristics of ultrabroadband LP conversion and significant AT effect through analysis of polarization azimuth rotation and ellipticity angles,total transmittance,AT coefficient,and electric field distribution.The proposed CMS structure shows excellent polarization conversion properties via AT effect and has potential applications in areas such as radar,remote sensing,and satellite communication.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52205114,51905349,U2013603)Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2022A1515010126,2023A1515012921,2020A1515011509)+1 种基金Excellent Science and Technology Creative Talent Training Program of Shenzhen,China(Grant No.RCBS20221008093252089)Shenzhen Natural Science Fund(the Stable Support Plan Program 20220809181431001)。
文摘Rotational energy is a type of common energy source that can be harvested for supplying low-powered electronic devices.This paper proposes and investigates a novel cam-like dielectric elastomer generator(CDEG)for high-performance rotational energy harvesting.A mushroom-head clamp is designed to form a type of advanced conical dielectric elastomer membranes(DEMs).Moreover,a type of multi-protrusion cam mechanism is designed in the CDEG to effectively convert any external rotational excitation into a linear reciprocating motion,which can be further converted into electricity through the DEMs.First,the operating principle of the system under external rotational excitation is analyzed theoretically by deducing the deformation condition of the DEMs and the electrical output of the system.Second,the prototype is fabricated,and the rotational-to-linear motion conversion rule of its cam-like mechanism and the DEM capacitance calculation approach are validated.The experimental results show that adequate charging time and discharging time of the DEMs,which can be realized through the proposed cam-like mechanisms,are beneficial to the energy harvesting(EH)performance of the system.Third,with the validated theoretical model,numerical simulations are conducted to further study the system dynamics and the influences of important system parameters on the EH performance to provide a guideline for system improvement.Finally,the genetic algorithm is adopted to obtain the optimal system parameters and the corresponding electrical output of the proposed CDEG,demonstrating its superior output power at ultralow rotational frequencies compared with other typical rotational energy harvesters in the literature.
文摘In this paper,we propose an ultrabroadband chiral metasurface(CMS)composed of S-shaped resonator structures situated between two twisted subwavelength gratings and dielectric substrate.This innovative structure enables ultrabroadband and high-efficiency linear polarization(LP)conversion,as well as asymmetric transmission(AT)effect in the microwave region.The enhanced interference effect of the Fabry-Perot-like resonance cavity greatly expands the bandwidth and efficiency of LP conversion and AT effect.Through numerical simulations,it has been revealed that the cross-polarization transmission coefficients for normal forward(-z)and backward(+z)incidence exceed 0.8 in the frequency range of 4.13 to 17.34 GHz,accompanied by a polarization conversion ratio of over 99%.Furthermore,our microwave experimental results validate the consistency among simulation,theory,and measurement.Additionally,we elucidate the distinct characteristics of ultrabroadband LP conversion and significant AT effect through analysis of polarization azimuth rotation and ellipticity angles,total transmittance,AT coefficient,and electric field distribution.The proposed CMS structure shows excellent polarization conversion properties via AT effect and has potential applications in areas such as radar,remote sensing,and satellite communication.
