Controlling electromagnetic(EM)waves at will is fundamentally important for diverse applications,ranging from optical microcavities,super-resolution imaging,to quantum information processing.Decades ago,the forays int...Controlling electromagnetic(EM)waves at will is fundamentally important for diverse applications,ranging from optical microcavities,super-resolution imaging,to quantum information processing.Decades ago,the forays into metamaterials and transformation optics have ignited unprecedented interest to create an invisibility cloak—a closed space with any object inside invisible.However,all features of the scattering waves become stochastic and uncontrollable when EM waves interact with an open and disordered environment,making an open invisible space almost impossible.Counterintuitively,here we for the first time present an open,cluttered,and dynamic but invisible space,wherein any freely-moving object maintains invisible.To adapt to the disordered environment,we randomly organize a swarm of reconfigurable metasurfaces,and master them by MetaSeeker,a population-based reinforcement learning(RL).MetaSeeker constructs a narcissistic internal world to mirror the stochastic physical world,capable of autonomous preferment,evolution,and adaptation.In the perception-decision-execution experiment,multiple RL agents automatically interact with the ever-changing environments and integrate a post-hoc explainability to visualize the decision-making process.The hidden objects,such as vehicle cluster and experimenter,can freely scale,race,and track in the invisible space,with the environmental similarity of 99.5%.Our results constitute a monumental stride to reshape the evolutionary landscape of metasurfaces from individual to swarm intelligence and usher in the remote management of entire EM space.展开更多
Being invisible ad libitum has long captivated the popular imagination,particularly in terms of safeguarding modern high-end instruments from potential threats.Decades ago,the advent of metamaterials and transformatio...Being invisible ad libitum has long captivated the popular imagination,particularly in terms of safeguarding modern high-end instruments from potential threats.Decades ago,the advent of metamaterials and transformation optics sparked considerable interest in invisibility cloaks,which have been mainly demonstrated in ground and waveguide modalities.However,an omnidirectional flying cloak has not been achieved,primarily due to the challenges associated with dynamic synthesis of metasurface dispersion.We demonstrate an autonomous aeroamphibious invisibility cloak that incorporates a suite of perception,decision,and execution modules,capable of maintaining invisibility amidst kaleidoscopic backgrounds and neutralizing external stimuli.The physical breakthrough lies in the spatiotemporal modulation imparted on tunable metasurfaces to sculpt the scattering field in both space and frequency domains.To intelligently control the spatiotemporal metasurfaces,we introduce a stochastic-evolution learning that automatically aligns with the optimal solution through maximum probabilistic inference.In a fully self-driving experiment,we implement this concept on an unmanned drone and showcase adaptive invisibility in three canonical landscapes-sea,land,and air-with a similarity rate of up to 95%.Our work extends the family of invisibility cloaks to flying modality and inspires other research on material discoveries and homeostatic meta-devices.展开更多
基金sponsored by the Key Research and Development Program of the Ministry of Science and Technology under Grant Nos.2022YFA1404704,2022YFA1405200,and 2022YFA1404902the National Natural Science Foundation of China(NNSFC)under Grant Nos.62422514,62471432,and 62101485+1 种基金the Key Research and Development Program of Zhejiang Province under Grant No.2022C01036the Fundamental Research Funds for the Central Universities.
文摘Controlling electromagnetic(EM)waves at will is fundamentally important for diverse applications,ranging from optical microcavities,super-resolution imaging,to quantum information processing.Decades ago,the forays into metamaterials and transformation optics have ignited unprecedented interest to create an invisibility cloak—a closed space with any object inside invisible.However,all features of the scattering waves become stochastic and uncontrollable when EM waves interact with an open and disordered environment,making an open invisible space almost impossible.Counterintuitively,here we for the first time present an open,cluttered,and dynamic but invisible space,wherein any freely-moving object maintains invisible.To adapt to the disordered environment,we randomly organize a swarm of reconfigurable metasurfaces,and master them by MetaSeeker,a population-based reinforcement learning(RL).MetaSeeker constructs a narcissistic internal world to mirror the stochastic physical world,capable of autonomous preferment,evolution,and adaptation.In the perception-decision-execution experiment,multiple RL agents automatically interact with the ever-changing environments and integrate a post-hoc explainability to visualize the decision-making process.The hidden objects,such as vehicle cluster and experimenter,can freely scale,race,and track in the invisible space,with the environmental similarity of 99.5%.Our results constitute a monumental stride to reshape the evolutionary landscape of metasurfaces from individual to swarm intelligence and usher in the remote management of entire EM space.
基金sponsored by the National Natural Science Foundation of China(Grant Nos.61625502,11961141010,61975176,62071424,and 62101485)the Young Elite Scientists Sponsorship Program by CAST(Grant No.2022QNRC001)+1 种基金the Top-Notch Young Talents Program of Chinathe Fundamental Research Funds for the Central Universities
文摘Being invisible ad libitum has long captivated the popular imagination,particularly in terms of safeguarding modern high-end instruments from potential threats.Decades ago,the advent of metamaterials and transformation optics sparked considerable interest in invisibility cloaks,which have been mainly demonstrated in ground and waveguide modalities.However,an omnidirectional flying cloak has not been achieved,primarily due to the challenges associated with dynamic synthesis of metasurface dispersion.We demonstrate an autonomous aeroamphibious invisibility cloak that incorporates a suite of perception,decision,and execution modules,capable of maintaining invisibility amidst kaleidoscopic backgrounds and neutralizing external stimuli.The physical breakthrough lies in the spatiotemporal modulation imparted on tunable metasurfaces to sculpt the scattering field in both space and frequency domains.To intelligently control the spatiotemporal metasurfaces,we introduce a stochastic-evolution learning that automatically aligns with the optimal solution through maximum probabilistic inference.In a fully self-driving experiment,we implement this concept on an unmanned drone and showcase adaptive invisibility in three canonical landscapes-sea,land,and air-with a similarity rate of up to 95%.Our work extends the family of invisibility cloaks to flying modality and inspires other research on material discoveries and homeostatic meta-devices.
